Showing 1–50 of 159 results for author: Tsumura, K

CIBER $\times$ galaxy cross-correlations reveal a bright, low-redshift NIR background

Authors: Richard M. Feder, Grigory Heaton, James J. Bock, Yun-Ting Cheng, Yi-Kuan Chiang, Phillip M. Korngut, Shuji Matsuura, Jordan Mirocha, Kohji Tsumura, Michael Zemcov

Abstract: We perform the first tomographic analysis of near-IR extragalactic background light (EBL) anisotropies, cross-correlating CIBER 1.1 and 1.8 $μ$m imager data with photometric galaxy catalogs from DESI Legacy Survey DR8 and Hyper-Suprime-Cam Ultra-Deep Survey. We measure significantly higher cross-power than expectations from an integrated galaxy light (IGL) model on scales $\ell < 2000$, concentrat… ▽ More We perform the first tomographic analysis of near-IR extragalactic background light (EBL) anisotropies, cross-correlating CIBER 1.1 and 1.8 $μ$m imager data with photometric galaxy catalogs from DESI Legacy Survey DR8 and Hyper-Suprime-Cam Ultra-Deep Survey. We measure significantly higher cross-power than expectations from an integrated galaxy light (IGL) model on scales $\ell < 2000$, concentrated at low redshift ($z\lesssim 0.6$). Cluster member galaxies and associated structure account for 15-20\% of the large-angle cross-power, indicating that group- and galaxy-scale halos contribute the bulk of the signal. Through a parametric halo model decomposition, we detect two-halo and one-halo clustering in cross-power at high significance, with amplitudes that decline smoothly across $z=0{-}1$. The inferred one-halo cross-power is of similar amplitude between DESI-LS and the deeper HSC catalog, implying a scenario in which low-redshift EBL fluctuations are amplified by contributions from lower-mass halos with satellites and/or diffuse intra-halo light (IHL). Converting our two-halo fits into estimates of $b_I \times dI/dz$, we find that standard IGL predictions underestimate our measurements, even when assuming an intensity bias as high as 3, similar to that of large SZ clusters, suggesting that a higher $dI/dz$ is required to reconcile observed discrepancies. Lastly, we find that correlated large-scale structure (LSS) at $z<1$ accounts for a substantial fraction of the CIBER auto-power reported in earlier work. These results identify low-redshift LSS as a significant and previously unappreciated contributor to near-IR EBL fluctuation measurements, setting the stage for cross-correlation science with CIBER-2, SPHEREx and a variety of LSS tracers. △ Less

Submitted 12 August, 2026; originally announced August 2026.

Comments: 29+12 pages, 12+10 figures, 3 tables. To be submitted to JCAP

Large-scale Morphology of the Optical F-corona from a Total Solar Eclipse Observation During the Artemis II Lunar Flyby

Authors: Kohji Tsumura, Ko Arimatsu

Abstract: We investigated the structure of the optical F-corona, i.e., inner zodiacal light, using a publicly released wide-field image of a total solar eclipse that was obtained during the Artemis~II crewed lunar flyby. In this image, the solar disk is fully occulted by the Moon, providing a rare view of diffuse circumsolar emission over a wide angular extent. Although the dataset is derived from a rendere… ▽ More We investigated the structure of the optical F-corona, i.e., inner zodiacal light, using a publicly released wide-field image of a total solar eclipse that was obtained during the Artemis~II crewed lunar flyby. In this image, the solar disk is fully occulted by the Moon, providing a rare view of diffuse circumsolar emission over a wide angular extent. Although the dataset is derived from a rendered RGB JPEG image without full photometric calibration, the gamma correction inherent to the image format was explicitly accounted for and the instrumental response was validated using field stars. The stellar calibration demonstrates a linear response within the unsaturated regime relevant to our measurements, enabling a reliable analysis of the relative morphology and brightness profiles of the F-corona. The observed F-corona exhibits a flattened, nearly elliptical morphology aligned with the ecliptic plane, with flattening indices of 0.52, 0.54, and 0.56 for the red, green, and blue channels, respectively. Radial intensity profiles along ecliptic longitude and latitude are well described by power laws in solar elongation, although the derived slopes are systematically steeper than previous observations. Comparison with the ZodiSURF zodiacal light model indicates that the observed radial profile of the F-corona along the ecliptic longitude is modestly reproduced by the model, supporting a radial dust number-density power-law index of $α$ ~1.3, even in regions near the Sun. In a broader historical context, these results provide an empirical proof-of-concept that supports future solar coronal occultation observations from lunar orbit. △ Less

Submitted 21 May, 2026; v1 submitted 15 April, 2026; originally announced April 2026.

Comments: 11 pages, 6 figures

Two component pseudo-Nambu-Goldstone-boson dark matter

Authors: Riasat Sheikh, Takashi Toma, Koji Tsumura

Abstract: We study a two-component pseudo-Nambu-Goldstone-boson (pNGB) dark matter (DM) model motivated by boosted dark matter (BDM). The model is based on a complex scalar field charged under a dark $\text{U}(1)_V$ gauge symmetry, with a softly broken global $\text{SU}(3)_g$ symmetry that is spontaneously broken. The pNGB nature suppresses DM--Nucleon scattering, while the residual… ▽ More We study a two-component pseudo-Nambu-Goldstone-boson (pNGB) dark matter (DM) model motivated by boosted dark matter (BDM). The model is based on a complex scalar field charged under a dark $\text{U}(1)_V$ gauge symmetry, with a softly broken global $\text{SU}(3)_g$ symmetry that is spontaneously broken. The pNGB nature suppresses DM--Nucleon scattering, while the residual $\text{U}(1)_3 \times \text{U}(1)_{T_0}$ symmetry automatically stabilizes the two pNGB DM candidates and allows conversion of the heavier component into the lighter one. A central point is that the heavier or light component hierarchy is controlled by the two independent soft-breaking parameters that split the pNGB multiplet, so an abundant heavier component required for BDM can be obtained without introducing ad hoc hierarchies among independent portal coupling tuned to enable effective conversion. We analyze the relic abundance together with the constraints considered in this work, including Higgs invisible decays and perturbative unitarity, classify the coupled freeze-out dynamics, and assess the resulting BDM scattering cross section and flux. △ Less

Submitted 14 April, 2026; originally announced April 2026.

Comments: 29 pages, 4 tables, 10 figures

Report number: KYUSHU-HET-359, KANAZAWA-26-01

The Cosmic Infrared Background Experiment-2: An Intensity Mapping Optimized Sounding-rocket Payload to Understand the Near-IR Extragalactic Background Light

Authors: Michael Zemcov, James J. Bock, Asantha Cooray, Shuji Matsuura, Dae-Hee Lee, Candice Fazar, Richard M. Feder, Grigory Heaton, Ryo Hashimoto, Phillip Korngut, Toshio Matsumoto, Chi H. Nguyen, Kazuma Noda, Won-Kee Park, Kei Sano, Kohji Takimoto, Toshiaki Arai, Seung-Cheol Bang, Priyadarshini Bangale, Masaki Furutani, Viktor Hristov, Yuya Kawano, Arisa Kida, Tomoya Kojima, Alicia Lanz , et al. (15 additional authors not shown)

Abstract: The background light produced by emission from all sources over cosmic history is a powerful diagnostic of structure formation and evolution. At near-infrared wavelengths, this extragalactic background light (EBL) is comprised of emission from galaxies stretching all the way back to the first-light objects present during the Epoch of Reionization. The Cosmic Infrared Background Experiment 2 (CIBER… ▽ More The background light produced by emission from all sources over cosmic history is a powerful diagnostic of structure formation and evolution. At near-infrared wavelengths, this extragalactic background light (EBL) is comprised of emission from galaxies stretching all the way back to the first-light objects present during the Epoch of Reionization. The Cosmic Infrared Background Experiment 2 (CIBER-2) is a sounding-rocket experiment designed to measure both the absolute photometric brightness of the EBL over 0.5 - 2.0 microns and perform an intensity mapping measurement of EBL spatial fluctuations in six broad bands over the same wavelength range. CIBER-2 comprises a 28.5 cm, 80K telescope that images several square degrees to three separate cameras. Each camera is equipped with an HAWAII-2RG detector covered by an assembly that combines two broadband filters and a linear-variable filter, which perform the intensity mapping and absolute photometric measurements, respectively. CIBER-2 has flown three times: an engineering flight in 2021; a terminated launch in 2023; and a successful science flight in 2024. In this paper, we review the science case for the experiment; describe the factors motivating the instrument design; review the optical, mechanical, and electronic implementation of the instrument; present preflight laboratory characterization measurements; and finally assess the instrument's performance in flight. △ Less

Submitted 6 October, 2025; originally announced October 2025.

Journal ref: Astrophysical Journal Supplement Series, Volume 280, Number 2, 2025

Status of the International Linear Collider

Authors: Y. Abe, S. Arai, S. Araki, H. Araki, Y. Arimoto, A. Aryshev, S. Asai, R. Bajpai, T. Behnke, S. Belomestnykh, I. Bozovic, J. E. Brau, K. Buesser, P. N. Burrows, N. Catalan-Lasheras, E. Cenni, S. Chen, J. Clark, D. Delikaris, M. Demarteau, D. Denisov, S. Doebert, T. Dohmae, R. Dowd, G. Dugan , et al. (127 additional authors not shown)

Abstract: This paper is not a proposal for a CERN future project but provides information on the International Linear Collider (ILC) considered for Japan in order to facilitate the European Strategy discussion in a global context. It describes progress to date, ongoing engineering studies, updated cost estimate for the machine at $\sqrt{s}=250~\rm GeV$ and the situation in Japan. The physics of the ILC is n… ▽ More This paper is not a proposal for a CERN future project but provides information on the International Linear Collider (ILC) considered for Japan in order to facilitate the European Strategy discussion in a global context. It describes progress to date, ongoing engineering studies, updated cost estimate for the machine at $\sqrt{s}=250~\rm GeV$ and the situation in Japan. The physics of the ILC is not presented here, but jointly for all Linear Collider projects in a separate document ``A Linear Collider Vision for the Future of Particle Physics'' submitted for the forthcoming European Strategy deliberations. △ Less

Submitted 5 June, 2025; v1 submitted 16 May, 2025; originally announced May 2025.

Pseudo-Nambu-Goldstone-boson Dark Matter from Three Complex Scalars

Authors: Riasat Sheikh, Takashi Toma, Koji Tsumura

Abstract: This study explores a dark matter model in which a pseudo-Nambu-Goldstone boson arises as a viable dark matter candidate from the spontaneous and soft breaking of global $\mathrm{U}(1)$ symmetries and stabilized by a residual $\mathbb{Z}_3$ discrete symmetry. The model introduces three complex scalar fields, singlets under the Standard Model gauge group, and charged under a dark $\mathrm{U}(1)_V$… ▽ More This study explores a dark matter model in which a pseudo-Nambu-Goldstone boson arises as a viable dark matter candidate from the spontaneous and soft breaking of global $\mathrm{U}(1)$ symmetries and stabilized by a residual $\mathbb{Z}_3$ discrete symmetry. The model introduces three complex scalar fields, singlets under the Standard Model gauge group, and charged under a dark $\mathrm{U}(1)_V$ gauge symmetry together with a permutative exchange symmetry among three scalars. These features naturally suppress the dark matter--nucleon scattering cross section by its Nambu-Goldstone boson nature. In addition to conventional annihilation channels, the $\mathbb{Z}_3$ structure allows semi-annihilation processes, playing a crucial role in setting the relic abundance.We analyze theoretical and experimental constraints, including relic abundance, Higgs invisible decays, and perturbative unitarity, and evaluate the elastic scattering cross section for boosted dark matter. △ Less

Submitted 5 August, 2025; v1 submitted 28 April, 2025; originally announced April 2025.

Comments: 17 pages, 5 figures; added appendix for section 2.2, references added, misc. corrections

Report number: KYUSHU-HET-319, KANAZAWA-25-01

Journal ref: J. High Energ. Phys. 2025, 18 (2025)

The Linear Collider Facility (LCF) at CERN

Authors: H. Abramowicz, E. Adli, F. Alharthi, M. Almanza-Soto, M. M. Altakach, S. Ampudia Castelazo, D. Angal-Kalinin, J. A. Anguiano, R. B. Appleby, O. Apsimon, A. Arbey, O. Arquero, D. Attié, J. L. Avila-Jimenez, H. Baer, Y. Bai, C. Balazs, P. Bambade, T. Barklow, J. Baudot, P. Bechtle, T. Behnke, A. B. Bellerive, S. Belomestnykh, Y. Benhammou , et al. (386 additional authors not shown)

Abstract: In this paper we outline a proposal for a Linear Collider Facility as the next flagship project for CERN. It offers the opportunity for a timely, cost-effective and staged construction of a new collider that will be able to comprehensively map the Higgs boson's properties, including the Higgs field potential, thanks to a large span in centre-of-mass energies and polarised beams. A comprehensive pr… ▽ More In this paper we outline a proposal for a Linear Collider Facility as the next flagship project for CERN. It offers the opportunity for a timely, cost-effective and staged construction of a new collider that will be able to comprehensively map the Higgs boson's properties, including the Higgs field potential, thanks to a large span in centre-of-mass energies and polarised beams. A comprehensive programme to study the Higgs boson and its closest relatives with high precision requires data at centre-of-mass energies from the Z pole to at least 1 TeV. It should include measurements of the Higgs boson in both major production mechanisms, ee -> ZH and ee -> vvH, precision measurements of gauge boson interactions as well as of the W boson, Higgs boson and top-quark masses, measurement of the top-quark Yukawa coupling through ee ->ttH, measurement of the Higgs boson self-coupling through HH production, and precision measurements of the electroweak couplings of the top quark. In addition, ee collisions offer discovery potential for new particles complementary to HL-LHC. △ Less

Submitted 19 June, 2025; v1 submitted 31 March, 2025; originally announced March 2025.

Comments: Submission to the ESPPU, as updated version May 26

Report number: DESY-25-054

A Linear Collider Vision for the Future of Particle Physics

Authors: H. Abramowicz, E. Adli, F. Alharthi, M. Almanza-Soto, M. M. Altakach, W. Altmannshofer, S. Ampudia Castelazo, D. Angal-Kalinin, J. A. Anguiano, R. B. Appleby, O. Apsimon, A. Arbey, F. Arco, O. Arquero, A. Aryshev, S. Asai, D. Attie, J. L. Avila-Jimenez, H. Baer, J. A. Bagger, Y. Bai, I. R. Bailey, C. Balazs, P. Bambade, T. Barklow , et al. (426 additional authors not shown)

Abstract: In this paper we review the physics opportunities at linear $e^+e^-$ colliders with a special focus on high centre-of-mass energies and beam polarisation, take a fresh look at the various accelerator technologies available or under development and, for the first time, discuss how a facility first equipped with a technology mature today could be upgraded with technologies of tomorrow to reach much… ▽ More In this paper we review the physics opportunities at linear $e^+e^-$ colliders with a special focus on high centre-of-mass energies and beam polarisation, take a fresh look at the various accelerator technologies available or under development and, for the first time, discuss how a facility first equipped with a technology mature today could be upgraded with technologies of tomorrow to reach much higher energies and/or luminosities. In addition, we will discuss detectors and alternative collider modes, as well as opportunities for beyond-collider experiments and R\&D facilities as part of a linear collider facility (LCF). The material of this paper will support all plans for $e^+e^-$ linear colliders and additional opportunities they offer, independently of technology choice or proposed site, as well as R\&D for advanced accelerator technologies. This joint perspective on the physics goals, early technologies and upgrade strategies has been developed by the LCVision team based on an initial discussion at LCWS2024 in Tokyo and a follow-up at the LCVision Community Event at CERN in January 2025. It heavily builds on decades of achievements of the global linear collider community, in particular in the context of CLIC and ILC. △ Less

Submitted 23 December, 2025; v1 submitted 25 March, 2025; originally announced March 2025.

Comments: Community document for EPPSU, major updates of several sections, in particular the global interpretation section

CIBER 4th flight fluctuation analysis: Measurements of near-IR auto- and cross-power spectra on arcminute to sub-degree scales

Authors: Richard M. Feder, James J. Bock, Yun-Ting Cheng, Asantha Cooray, Phillip M. Korngut, Shuji Matsuura, Jordan Mirocha, Chi H. Nguyen, Kohji Takimoto, Kohji Tsumura, Ryan Wills, Michael Zemcov, CIBER collaboration

Abstract: We present new anisotropy measurements in the near-infrared (NIR) for angular multipoles $300<\ell<10^5$ using imaging data at 1.1 $μ$m and 1.8 $μ$m from the fourth flight of the Cosmic Infrared Background ExpeRiment (CIBER). Using improved analysis methods and higher quality fourth flight data, we detect surface brightness fluctuations on scales $\ell<2000$ with CIBER auto-power spectra at… ▽ More We present new anisotropy measurements in the near-infrared (NIR) for angular multipoles $300<\ell<10^5$ using imaging data at 1.1 $μ$m and 1.8 $μ$m from the fourth flight of the Cosmic Infrared Background ExpeRiment (CIBER). Using improved analysis methods and higher quality fourth flight data, we detect surface brightness fluctuations on scales $\ell<2000$ with CIBER auto-power spectra at $\sim14σ$ and 18$σ$ for 1.1 and 1.8 $μ$m, respectively, and at $\sim10σ$ in cross-power spectra. The CIBER measurements pass internal consistency tests and represent a $5-10\times$ improvement in power spectrum sensitivity on several-arcminute scales relative to that of existing studies. Through cross-correlations with tracers of diffuse galactic light (DGL), we determine that scattered DGL contributes $<10\%$ to the observed fluctuation power at high confidence. On scales $θ> 5'$, the CIBER auto- and cross-power spectra exceed predictions for integrated galactic light (IGL) and integrated stellar light (ISL) by over an order of magnitude, and are inconsistent with our baseline IGL+ISL+DGL model at high significance. We cross-correlate two of the CIBER fields with 3.6 $μ$m and 4.5 $μ$m mosaics from the Spitzer Deep Wide-Field Survey and find similar evidence for departures from Poisson noise in Spitzer-internal power spectra and CIBER $\times$ Spitzer cross-power spectra. A multi-wavelength analysis indicates that the auto-power of the fluctuations at low-$\ell$ is bluer than the Poisson noise from IGL and ISL; however, for $1' <θ< 10'$, the cross-correlation coefficient $r_{\ell}$ of nearly all band combinations decreases with increasing $θ$, disfavoring astrophysical explanations that invoke a single correlated sky component. △ Less

Submitted 29 January, 2025; originally announced January 2025.

Comments: 41 pages, 32 figures. Submitted to ApJ

Nambu-Goldstone Modes in Magnetized $T^{2n}$ Extra Dimensions

Authors: Takuya Hirose, Hajime Otsuka, Koji Tsumura, Yoshiki Uchida

Abstract: We consider a $U(1)$ gauge theory on $M^4\times T^4$ with background magnetic fluxes. We show that a theory including arbitrary fluxes can always be studied in a theory involving only diagonal fluxes by appropriate coordinate transformations. It is found that the number of independent magnetic fluxes is equal to the rank of the classical value of the field strength matrix,… ▽ More We consider a $U(1)$ gauge theory on $M^4\times T^4$ with background magnetic fluxes. We show that a theory including arbitrary fluxes can always be studied in a theory involving only diagonal fluxes by appropriate coordinate transformations. It is found that the number of independent magnetic fluxes is equal to the rank of the classical value of the field strength matrix, ${\rm rank}\langle F\rangle$. The number of massless zero modes induced from extra components of higher-dimensional gauge field (Wilson-line scalar field), is also determined by ${\rm rank}\langle F\rangle$. We explicitly confirm that the quantum corrections due to the matter fermion to the squared mass of Wilson-line scalar field cancel out at one-loop level. For this purpose, we derive the fermion mass spectrum on $M^4\times T^4$ with arbitrary fluxes. By taking the flux diagonal basis, creation and annihilation operators for Kaluza-Klein quantum numbers are defined appropriately. Our results are easily generalized to the case of $M^4\times T^{2n}~(n\geq3)$. △ Less

Submitted 2 September, 2024; v1 submitted 25 March, 2024; originally announced March 2024.

Comments: 17 pages, 2 figures

Report number: KYUSHU-HET-284

New Constraints on Gauged U(1)$_{L_μ-L_τ}$ Models via $Z-Z'$ Mixing

Authors: Kento Asai, Coh Miyao, Shohei Okawa, Koji Tsumura

Abstract: It is known that the model based on U(1)$_{L_μ-L_τ}$ gauge symmetry can explain not only the discrepancy between the measured value of muon $g-2$ and the theoretical prediction, but also the structure of the neutrino mass and mixings. We revisit the analysis of the mass matrix structure in the minimal U(1)$_{L_μ-L_τ}$ models based on the latest experimental result, where the minimal stands for the… ▽ More It is known that the model based on U(1)$_{L_μ-L_τ}$ gauge symmetry can explain not only the discrepancy between the measured value of muon $g-2$ and the theoretical prediction, but also the structure of the neutrino mass and mixings. We revisit the analysis of the mass matrix structure in the minimal U(1)$_{L_μ-L_τ}$ models based on the latest experimental result, where the minimal stands for the symmetry breaking caused only by a single scalar field. We find that the model called type ${\bf 2}_{+1}$, where an SU(2)$_L$ doublet scalar $Φ_{+1}$ with the U(1)$_{L_μ- L_τ}$ charge $+1$ and the hypercharge $+1/2$, predicts the $\bf B_3$ texture and is marginally acceptable under the current neutrino oscillation data and cosmological observation. When the U(1)$_{L_μ- L_τ}$ gauge symmetry is broken by the vacuum expectation value of the standard model non-singlet representation such as $Φ_{+1}$, there are additional contributions to the flavor-changing meson decay process and atomic parity violation via the $Z-Z'$ mixing. We newly evaluate the model-dependent constraints on the model and conclude that the type ${\bf 2}_{+1}$ model is robustly ruled out. The model is extended to have an additional vacuum expectation value of a standard model singlet scalar in order to avoid the stringent constraint from the flavor-changing meson decay. Finally, we find the allowed range of the ratio of these vacuum expectation values. △ Less

Submitted 9 December, 2024; v1 submitted 31 January, 2024; originally announced January 2024.

Report number: KYUSHU-HET-280, KEK-TH-2597

Journal ref: JHEP 12, 2024, 018

A model of pseudo-Nambu-Goldstone dark matter with two complex scalars

Authors: Tomohiro Abe, Yu Hamada, Koji Tsumura

Abstract: Pseudo-Nambu-Goldstone (pNG) dark matter (DM) is a promising DM candidate and able to explain the measured DM abundance by the thermal freeze-out mechanism evading the stringent bound from DM direct detection experiments. We propose a new model providing a pNG DM by introducing two Standard-Model-singlet complex scalars with the same charges of a dark $U(1)$ gauge symmetry. They are also charged u… ▽ More Pseudo-Nambu-Goldstone (pNG) dark matter (DM) is a promising DM candidate and able to explain the measured DM abundance by the thermal freeze-out mechanism evading the stringent bound from DM direct detection experiments. We propose a new model providing a pNG DM by introducing two Standard-Model-singlet complex scalars with the same charges of a dark $U(1)$ gauge symmetry. They are also charged under a $U(1)$ global symmetry corresponding to their relative phase rotations, which is explicitly broken by a soft-breaking term in the scalar potential. The both $U(1)$ symmetries are spontaneously broken by their vacuum expectation values, giving rise to one real pNG boson. We also introduce a discrete $\mathbb{Z}_2$ symmetry exchanging the two scalars to stabilize the pNG boson as DM. It is shown that this model reproduces the DM abundance consistently with the current bound from the direct detection experiments. The model has a gauge kinetic mixing between the dark and $U(1)_Y$ gauge fields, which allows the dark gauge boson to decay even with a relatively light mass and prevents it from being an additional DM component. The Landau pole is avoided thanks to the small gauge coupling constant. In addition, a DM pair dominantly annihilates into a pair of the dark gauge bosons if the gauge boson mass is lighter than the DM mass, and thus its cross section has significantly different parameter dependence from other pNG DM models. We also calculate the DM-nucleon scattering cross section at the loop level. It turns out that it is necessary to probe region covered by the neutrino fog in order to test this model. △ Less

Submitted 30 April, 2024; v1 submitted 4 January, 2024; originally announced January 2024.

Comments: 31 pages, 10 figures; v2 published version

Report number: KEK-TH-2589, DESY-24-002, KYUSHU-HET-277

Pseudo-Nambu-Goldstone Dark Matter in $SU(7)$ Grand Unification

Authors: Cheng-Wei Chiang, Koji Tsumura, Yoshiki Uchida, Naoki Yamatsu

Abstract: We propose a grand unified theory (GUT) pseudo-Nambu-Goldstone boson (pNGB) dark matter (DM) model based on $SU(7)$ gauge symmetry. In the GUT model, the Standard Model (SM) gauge symmetry $G_{\rm SM} := SU(3)_C\times SU(2)_L\times U(1)_Y$ and the ``dark'' gauge symmetry $SU(2)_D$ are unified, where the $SU(2)_D$ symmetry plays an important role in the stability of DM. The unification of SM fermio… ▽ More We propose a grand unified theory (GUT) pseudo-Nambu-Goldstone boson (pNGB) dark matter (DM) model based on $SU(7)$ gauge symmetry. In the GUT model, the Standard Model (SM) gauge symmetry $G_{\rm SM} := SU(3)_C\times SU(2)_L\times U(1)_Y$ and the ``dark'' gauge symmetry $SU(2)_D$ are unified, where the $SU(2)_D$ symmetry plays an important role in the stability of DM. The unification of SM fermions and dark sector fermions is partially realized. The gauge symmetry $SU(7)$ is spontaneously broken to $SU(5)\times SU(2)\times U(1)$ gauge symmetry at the GUT scale by the nonvanishing vacuum expectation values of an $SU(7)$ adjoint scalar field. The symmetry is further broken to $G_{\rm SM}\times SU(2)_D$ at an intermediate scale. Furthermore, the $SU(2)_D$ symmetry is broken by the $SU(2)_D$ doublet and triplet scalar fields at the TeV scale. In the pNGB DM model based on $G_{\rm SM}\times SU(2)_D$, the residual global $U(1)_V$ dark custodial symmetry guarantees DM stability. On the other hand, in the $SU(7)$ pNGB DM model, this global symmetry is explicitly broken by the Yukawa interaction and the effective Majorana mass terms. To maintain $U(1)_V$ symmetry and thus the DM stability, we need to tune Yukawa coupling constants and cubic scalar couplings at high accuracy. We find that the allowed DM mass region is quite restricted as the gauge coupling constant of $SU(2)_D$ is determined by the condition of the gauge coupling unification. To satisfy gauge coupling unification and the current experimental constraint on proton lifetime, we find that three generations of $SU(3)_C$ adjoint fermions and another three generations of $SU(2)_L$ adjoint fermions with the intermediate mass scale are required. We also find that there is no other solution to satisfy simultaneously the gauge coupling unification and the proton decay constraint if one assumes the other symmetry breaking schemes. △ Less

Submitted 25 March, 2024; v1 submitted 22 November, 2023; originally announced November 2023.

Comments: 25 pages, 6 tables, 4 figures; some paragraphs added; typos corrected; accepted for publication in Physical Review D

Report number: KYUSHU-HET-272

Cloud reflection modelling for impact flashes on Jupiter: A new constraint on the bulk properties of the impact objects

Authors: Ko Arimatsu, Kohji Tsumura, Fumihiko Usui, Jun-ichi Watanabe

Abstract: We investigate optical characteristics of flashes caused by impacting meter- to decameter-sized outer solar system objects on Jupiter and contributions of reflected light from surface clouds at visible wavelengths to estimate more accurate bulk parameters such as the luminous energy of the flash, the kinetic energy, the mass, and the size of the impact object. Based on the results of recent reflec… ▽ More We investigate optical characteristics of flashes caused by impacting meter- to decameter-sized outer solar system objects on Jupiter and contributions of reflected light from surface clouds at visible wavelengths to estimate more accurate bulk parameters such as the luminous energy of the flash, the kinetic energy, the mass, and the size of the impact object. Based on the results of recent reflectivity studies of the Jovian surface, we develop a cloud reflection model that calculates the contribution of the reflected light relative to that directly from the flash. We compare the apparent luminous energy of the previously reported flashes with the expected cloud reflection contributions to obtain their revised bulk parameters. We found that the cloud reflection contributions can be up to 200% of the flux directly from the flash and thus can be the most significant uncertainty in the measurement of the bulk parameters. The reflection contributions strongly depend on wavelength. With our cloud reflection correction, the revised bulk parameters of the previously reported flashes are obtained. Our cloud reflection correction provides a better understanding of the properties of impacting objects on Jupiter and is crucial for ongoing detailed investigations using high-sensitivity and multi-wavelength observation systems such as PONCOTS. It will also be useful for understanding other optical transients in Jupiter's upper atmosphere, such as the recently discovered sprite-like events. △ Less

Submitted 2 August, 2023; originally announced August 2023.

Comments: 6 pages, 4 figures, accepted for publication in Astronomy & Astrophysics

Journal ref: A&A 677, A165 (2023)

Modelling the optical energy profile of the 2021 October Jupiter impact flash

Authors: Ko Arimatsu, Kohji Tsumura, Fumihiko Usui, Jun-ichi Watanabe

Abstract: We have conducted numerical simulations to reproduce the observed optical energy profile of the 15 October 2021 (UT) impact flash on Jupiter, which was the largest and the most well-observed flash event detected by ground-based movie observations. The observed long-duration ($\sim 5.5~{\rm s}$) optical emission can be reproduced by an impact of an object with an exceptionally small angle of entry… ▽ More We have conducted numerical simulations to reproduce the observed optical energy profile of the 15 October 2021 (UT) impact flash on Jupiter, which was the largest and the most well-observed flash event detected by ground-based movie observations. The observed long-duration ($\sim 5.5~{\rm s}$) optical emission can be reproduced by an impact of an object with an exceptionally small angle of entry relative to the horizontal. The apparent lack of the impact debris feature despite the large impact object was possibly due to the shallower angle of entry ($\le 12^\circ$), which resulted in the lower ablation per unit volume at altitudes higher than $50 \, {\rm km}$, and the volume densities of the ablated materials were too low to allow the debris particulates to coagulate. The absence of temporal methane absorption change in the observed flash spectrum is consistent with the best-fit results. The model better fits the observed optical energy profile for weaker material (cometary and stony) cases than for metallic ones. Based on the simulation results, prospects for future observations of impact flashes are discussed. △ Less

Submitted 4 April, 2023; originally announced April 2023.

Comments: 6 pages, 5 figures, Accepted for publication in MNRAS

Heliocentric Distance Dependence of Zodiacal Light Observed by Hayabusa2#

Authors: Kohji Tsumura, Shuji Matsuura, Kei Sano, Takahiro Iwata, Hajime Yano, Kohei Kitazato, Kohji Takimoto, Manabu Yamada, Tomokatsu Morota, Toru Kouyama, Masahiko Hayakawa, Yasuhiro Yokota, Eri Tatsumi, Moe Matsuoka, Naoya Sakatani, Rie Honda, Shingo Kameda, Hidehiko Suzuki, Yuichiro Cho, Kazuo Yoshioka, Kazunori Ogawa, Kei Shirai, Hirotaka Sawada, Seiji Sugita

Abstract: Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as $n(r) \sim r^{-α}$, and the exponent $α\sim 1.3$ was obtained by previous obse… ▽ More Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as $n(r) \sim r^{-α}$, and the exponent $α\sim 1.3$ was obtained by previous observations from interplanetary space by Helios 1/2 and Pioneer 10/11 in the 1970s and 1980s. However, no direct measurements of $α$ based on ZL observations from interplanetary space outside Earth's orbit have been performed since then. Here, we introduce initial results for the radial profile of the ZL at optical wavelengths observed over the range 0.76-1.06 au by ONC-T aboard the Hayabusa2# mission in 2021-2022. The ZL brightness we obtained is well reproduced by a model brightness, although there is a small excess of the observed ZL brightness over the model brightness at around 0.9 au. The radial power-law index we obtained is $α= 1.30 \pm 0.08$, which is consistent with previous results based on ZL observations. The dominant source of uncertainty arises from the uncertainty in estimating the diffuse Galactic light (DGL). △ Less

Submitted 6 July, 2023; v1 submitted 13 March, 2023; originally announced March 2023.

Comments: 22 pages, 19 figures, 4 tables, accepted for publication by Earth, Planets and Space

Pseudo-Nambu-Goldstone Dark Matter from Non-Abelian Gauge Symmetry

Authors: Hajime Otsuka, Takashi Shimomura, Koji Tsumura, Yoshiki Uchida, Naoki Yamatsu

Abstract: We propose a pseudo-Nambu-Goldstone boson (pNGB) dark matter (DM) model based on an additional non-Abelian gauge symmetry $SU(2)_D$. The gauge symmetry $SU(2)_D$ is spontaneously broken to a global custodial symmetry $U(1)_V$ via the nonvanishing vacuum expectation values of $SU(2)_D$ doublet and triplet scalar fields. Due to the exact global symmetry $U(1)_V$, the lightest $U(1)_V$ charged partic… ▽ More We propose a pseudo-Nambu-Goldstone boson (pNGB) dark matter (DM) model based on an additional non-Abelian gauge symmetry $SU(2)_D$. The gauge symmetry $SU(2)_D$ is spontaneously broken to a global custodial symmetry $U(1)_V$ via the nonvanishing vacuum expectation values of $SU(2)_D$ doublet and triplet scalar fields. Due to the exact global symmetry $U(1)_V$, the lightest $U(1)_V$ charged particle becomes stable. We assume that the lightest charged particle in the model is the charged complex pNGB, which we regard as DM. It avoids the strong constraints from current DM direct detection experiments due to the property of NGB. We find that the measured energy density of DM can be reproduced when the DM mass is larger than the half of the Higgs mass, where the lower limit generally comes from the constraint of DM invisible decay and the upper limit from DM direct detection experiments depends on the model parameters. △ Less

Submitted 1 December, 2022; v1 submitted 16 October, 2022; originally announced October 2022.

Comments: 23 pages, 3 tables, 6 figures; some references added; accepted for publication in Physical Review D

Report number: KYUSHU-HET-246, UME-PP-022

Detection of an extremely large impact flash on Jupiter by high-cadence multiwavelength observations

Authors: Ko Arimatsu, Kohji Tsumura, Fumihiko Usui, Jun-ichi Watanabe

Abstract: We report the detection of an optical impact flash on Jupiter on 15 October 2021 by a dedicated telescope, Planetary ObservatioN Camera for Optical Transient Surveys (PONCOTS), for the first time. Our temporally resolved three-band observations of the flash allowed investigations of its optical energy without the need for approximations on the impact brightness temperature. The kinetic energy of t… ▽ More We report the detection of an optical impact flash on Jupiter on 15 October 2021 by a dedicated telescope, Planetary ObservatioN Camera for Optical Transient Surveys (PONCOTS), for the first time. Our temporally resolved three-band observations of the flash allowed investigations of its optical energy without the need for approximations on the impact brightness temperature. The kinetic energy of the impactor was equivalent to approximately two megatons of TNT, an order of magnitude greater than that of previously detected flashes on Jupiter and comparable with the Tunguska impact on Earth in 1908. This detection indicates that Tunguska-like impact events on Jupiter occur approximately once per year, two-three orders of magnitude more frequent than terrestrial impacts. The observed flash displayed a single-temperature blackbody spectrum with an effective temperature of approximately 8300 K without clear temporal variation, possibly representing common radiative features of terrestrial Tunguska-class superbolides. △ Less

Submitted 2 June, 2022; originally announced June 2022.

Comments: 13 pages, 6 figures, ApJL accepted

Scalar Dark Matter with a $μτ$ Flavored Mediator

Authors: Kento Asai, Coh Miyao, Shohei Okawa, Koji Tsumura

Abstract: We study a renormalizable scalar singlet dark matter model based on $Z_4$ lepton flavor symmetry. A $μτ$-philic scalar doublet is introduced to explain the discrepancy between the experimental value and the theoretical prediction of the muon anomalous magnetic moment. At the same time, these flavored scalars play the role of a mediator which connects dark matter and standard model particles. The o… ▽ More We study a renormalizable scalar singlet dark matter model based on $Z_4$ lepton flavor symmetry. A $μτ$-philic scalar doublet is introduced to explain the discrepancy between the experimental value and the theoretical prediction of the muon anomalous magnetic moment. At the same time, these flavored scalars play the role of a mediator which connects dark matter and standard model particles. The observed relic abundance of the dark matter is easily maintained while satisfying the current severe constraints on the dark matter from various experiments and observations thanks to the flavor off-diagonal interactions of scalar mediators. We also explore the possibility of dark matter direct detection through the one-loop process. △ Less

Submitted 20 November, 2022; v1 submitted 18 May, 2022; originally announced May 2022.

Comments: 17 pages, 5 figures; v2 : matches version published in PRD

Report number: KYUSHU-HET-241

The International Linear Collider: Report to Snowmass 2021

Authors: Alexander Aryshev, Ties Behnke, Mikael Berggren, James Brau, Nathaniel Craig, Ayres Freitas, Frank Gaede, Spencer Gessner, Stefania Gori, Christophe Grojean, Sven Heinemeyer, Daniel Jeans, Katja Kruger, Benno List, Jenny List, Zhen Liu, Shinichiro Michizono, David W. Miller, Ian Moult, Hitoshi Murayama, Tatsuya Nakada, Emilio Nanni, Mihoko Nojiri, Hasan Padamsee, Maxim Perelstein , et al. (487 additional authors not shown)

Abstract: The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This docu… ▽ More The International Linear Collider (ILC) is on the table now as a new global energy-frontier accelerator laboratory taking data in the 2030s. The ILC addresses key questions for our current understanding of particle physics. It is based on a proven accelerator technology. Its experiments will challenge the Standard Model of particle physics and will provide a new window to look beyond it. This document brings the story of the ILC up to date, emphasizing its strong physics motivation, its readiness for construction, and the opportunity it presents to the US and the global particle physics community. △ Less

Submitted 16 January, 2023; v1 submitted 14 March, 2022; originally announced March 2022.

Comments: 356 pages, Large pdf file (40 MB) submitted to Snowmass 2021; v2 references to Snowmass contributions added, additional authors; v3 references added, some updates, additional authors

Report number: DESY-22-045, IFT--UAM/CSIC--22-028, KEK Preprint 2021-61, PNNL-SA-160884, SLAC-PUB-17662

Polarization spectrum of near infrared zodiacal light observed with CIBER

Authors: Kohji Takimoto, Toshiaki Arai, Shuji Matsuura, James J. Bock, Asantha Cooray, Richard M. Feder, Phillip M. Korngut, Alicia Lanz, Dae Hee Lee, Toshio Matsumoto, Chi H. Nguyen, Yosuke Onishi, Kei Sano, Mai Shirahata, Aoi Takahashi, Kohji Tsumura, Michael Zemcov

Abstract: We report the first measurement of the zodiacal light (ZL) polarization spectrum in the near-infrared between 0.8 and 1.8 $μ$m. Using the low-resolution spectrometer (LRS) on board the Cosmic Infrared Background Experiment (CIBER), calibrated for absolute spectrophotometry and spectropolarimetry, we acquire long-slit polarization spectral images of the total diffuse sky brightness towards five fie… ▽ More We report the first measurement of the zodiacal light (ZL) polarization spectrum in the near-infrared between 0.8 and 1.8 $μ$m. Using the low-resolution spectrometer (LRS) on board the Cosmic Infrared Background Experiment (CIBER), calibrated for absolute spectrophotometry and spectropolarimetry, we acquire long-slit polarization spectral images of the total diffuse sky brightness towards five fields. To extract the ZL spectrum, we subtract contribution of other diffuse radiation, such as the diffuse galactic light (DGL), the integrated star light (ISL), and the extragalactic background light (EBL). The measured ZL polarization spectrum shows little wavelength dependence in the near-infrared and the degree of polarization clearly varies as a function of the ecliptic coordinates and solar elongation. Among the observed fields, the North Ecliptic Pole shows the maximum degree of polarization of $\sim$ 20$\%$, which is consistent with an earlier observation from the Diffuse Infrared Background Experiment (DIRBE) aboard on the Cosmic Background Explorer (COBE). The measured degree of polarization and its solar elongation dependence are reproduced by the empirical scattering model in the visible band and also by the Mie scattering model for large absorptive particles, while the Rayleigh scattering model is ruled out. All of our results suggest that the interplanetary dust is dominated by large particles. △ Less

Submitted 10 December, 2021; originally announced December 2021.

Comments: 15 pages, 15 figures, accepted by ApJ

Baryon number non-conservation as Peccei-Quinn mechanism

Authors: Takahiro Ohata, Kengo Takeuchi, Koji Tsumura

Abstract: Baryon number is an accidental symmetry in the standard model, while Peccei-Quinn symmetry is hypothetical symmetry which is introduced to solve the strong CP problem. We study the possible connections between Peccei-Quinn symmetry and baryon number symmetry. In this framework, an axion is identified as the Nambu-Goldstone boson of baryon number violation. As a result, characteristic baryon number… ▽ More Baryon number is an accidental symmetry in the standard model, while Peccei-Quinn symmetry is hypothetical symmetry which is introduced to solve the strong CP problem. We study the possible connections between Peccei-Quinn symmetry and baryon number symmetry. In this framework, an axion is identified as the Nambu-Goldstone boson of baryon number violation. As a result, characteristic baryon number violating processes are predicted. We developed the general method to determine the baryon number and lepton number of new scalar in the axion model. △ Less

Submitted 28 August, 2021; v1 submitted 29 April, 2021; originally announced April 2021.

Comments: 19 pages, 6 figures, version accepted in PRD

Report number: KYUSHU-HET-223, KUNS-2862

Journal ref: Phys. Rev. D 104, 035026 (2021)

Pseudo-Nambu-Goldstone Dark Matter Model Inspired by Grand Unification

Authors: Yoshihiko Abe, Takashi Toma, Koji Tsumura, Naoki Yamatsu

Abstract: A pseudo-Nambu-Goldstone boson (pNGB) is an attractive candidate for dark matter (DM) due to the simple evasion of the current severe limits of DM direct detection experiments. One of the pNGB DM models has been proposed based on a {\it gauged} $U(1)_{B-L}$ symmetry. The pNGB has long enough lifetime to be a DM and thermal relic abundance of pNGB DM can be fit with the observed value against the c… ▽ More A pseudo-Nambu-Goldstone boson (pNGB) is an attractive candidate for dark matter (DM) due to the simple evasion of the current severe limits of DM direct detection experiments. One of the pNGB DM models has been proposed based on a {\it gauged} $U(1)_{B-L}$ symmetry. The pNGB has long enough lifetime to be a DM and thermal relic abundance of pNGB DM can be fit with the observed value against the constraints on the DM decays from the cosmic-ray observations. The pNGB DM model can be embedded into an $SO(10)$ pNGB DM model in the framework of an $SO(10)$ grand unified theory, whose $SO(10)$ is broken to the Pati-Salam gauge group at the unified scale, and further to the Standard Model gauge group at the intermediate scale. Unlike the previous pNGB DM model, the parameters such as the gauge coupling constants of $U(1)_{B-L}$, the kinetic mixing parameter of between $U(1)_Y$ and $U(1)_{B-L}$ are determined by solving the renormalization group equations for gauge coupling constants with appropriate matching conditions. From the constraints of the DM lifetime and gamma-ray observations, the pNGB DM mass must be less than $\mathcal{O}(100)$$\,$GeV. We find that the thermal relic abundance can be consistent with all the constraints when the DM mass is close to half of the CP even Higg masses. △ Less

Submitted 28 July, 2021; v1 submitted 27 April, 2021; originally announced April 2021.

Comments: 26 pages, 6 tables, 5 figures; typos corrected; some figures replaced; some references and paragraphs added; accepted for publication in Physical Review D

Report number: KUNS-2865, KYUSHU-HET-225, KANAZAWA-21-04

Journal ref: Phys. Rev. D 104, 035011 (2021)

Hayabusa2 Extended Mission: New Voyage to Rendezvous with a Small Asteroid Rotating with a Short Period

Authors: M. Hirabayashi, Y. Mimasu, N. Sakatani, S. Watanabe, Y. Tsuda, T. Saiki, S. Kikuchi, T. Kouyama, M. Yoshikawa, S. Tanaka, S. Nakazawa, Y. Takei, F. Terui, H. Takeuchi, A. Fujii, T. Iwata, K. Tsumura, S. Matsuura, Y. Shimaki, S. Urakawa, Y. Ishibashi, S. Hasegawa, M. Ishiguro, D. Kuroda, S. Okumura , et al. (19 additional authors not shown)

Abstract: Hayabusa2 is the Japanese Asteroid Return Mission and targeted the carbonaceous asteroid Ryugu, conducted by the Japan Aerospace Exploration Agency (JAXA). The goal of this mission was to conduct proximity operations including remote sensing observations, material sampling, and a Small Carry-On Impact experiment, as well as sample analyses. As of September 2020, the spacecraft is on the way back t… ▽ More Hayabusa2 is the Japanese Asteroid Return Mission and targeted the carbonaceous asteroid Ryugu, conducted by the Japan Aerospace Exploration Agency (JAXA). The goal of this mission was to conduct proximity operations including remote sensing observations, material sampling, and a Small Carry-On Impact experiment, as well as sample analyses. As of September 2020, the spacecraft is on the way back to Earth with samples from Ryugu with no critical issues after the successful departure in November 2019. Here, we propose an extended mission in which the spacecraft will rendezvous with a small asteroid with ~30 m - ~40 m in diameter that is rotating at a spin period of ~10 min after an additional ~10-year cruise phase. We introduce that two scenarios are suitable for the extended mission. In the first scenario, the spacecraft will perform swing-by maneuvers at Venus once and Earth twice to arrive at asteroid 2001 AV43. In the second scenario, it will perform swing-by maneuvers at Earth twice to reach asteroid 1998 KY26. In both scenarios, the mission will continue until the early 2030s. JAXA recently released the decision that the spacecraft will rendezvous with 1998 KY26. This paper focuses on our scientific assessments of the two scenarios but leaves the decision process to go to 1998 KY26 for future reports. Rendezvous operations will be planned to detail the physical properties and surrounding environments of the target, one of the smallest elements of small planetary bodies. By achieving the planned operations, the mission will provide critical hints on the violent histories of collisions and accumulations of small bodies in the solar system. Furthermore, the established scientific knowledge and techniques will advance key technologies for planetary defense. △ Less

Submitted 17 April, 2021; originally announced April 2021.

Comments: 51 pages, 9 figures, and 10 tables. The article is in press in Advances in Space Research

Measurements of the Zodiacal Light Absolute Intensity through Fraunhofer Absorption Line Spectroscopy with CIBER

Authors: Phillip Korngut, Min Gyu Kim, Toshiaki Arai, Priyadarshini Bangale, James Bock, Asantha Cooray, Yun Ting Cheng, Richard Feder, Viktor Hristov, Alicia Lanz, Louis Levenson, Toshio Matsumoto, Shuji Matsuura, Chi Nguyen, Kei Sano, Kohji Tsumura, Michael Zemcov

Abstract: Scattered sunlight from the interplanetary dust (IPD) cloud in our Solar system presents a serious foreground challenge for spectro-photometric measurements of the Extragalactic Background Light (EBL). In this work, we report on measurements of the absolute intensity of the Zodiacal Light (ZL) using the novel technique of Fraunhofer line spectroscopy on the deepest 8542 Angstrom line of the near-i… ▽ More Scattered sunlight from the interplanetary dust (IPD) cloud in our Solar system presents a serious foreground challenge for spectro-photometric measurements of the Extragalactic Background Light (EBL). In this work, we report on measurements of the absolute intensity of the Zodiacal Light (ZL) using the novel technique of Fraunhofer line spectroscopy on the deepest 8542 Angstrom line of the near-infrared CaII absorption triplet. The measurements are performed with the Narrow Band Spectrometer (NBS) aboard the Cosmic Infrared Background Experiment (CIBER) sounding rocket instrument. We use the NBS data to test the accuracy of two ZL models widely cited in the literature; the Kelsall and Wright models, which have been used in foreground removal analyses that produce high and low EBL results respectively. We find a mean reduced chi squared of 3.5 for the Kelsall model and a chi squared of 2.0 for the Wright model. The best description of our data is provided by a simple modification to the Kelsall model which includes a free ZL offset parameter. This adjusted model describes the data with a reduced chi squared of 1.5 and yields an inferred offset amplitude of 46 +- 19 nW m^-2 sr^-1 extrapolated to 12500 Angstroms. These measurements elude to the potential existence of a dust cloud component in the inner Solar system whose intensity does not strongly modulate with the Earth's motion around the Sun. △ Less

Submitted 14 April, 2021; originally announced April 2021.

Probing Intra-Halo Light with Galaxy Stacking in CIBER Images

Authors: Yun-Ting Cheng, Toshiaki Arai, Priyadarshini Bangale, James J. Bock, Tzu-Ching Chang, Asantha Cooray, Richard M. Feder, Phillip M. Korngut, Dae Hee Lee, Lunjun Liu, Toshio Matsumoto, Shuji Matsuura, Chi H. Nguyen, Kei Sano, Kohji Tsumura, Michael Zemcov

Abstract: We study the stellar halos of $0.2\lesssim z \lesssim 0.5$ galaxies with stellar masses spanning $M_*\sim 10^{10.5}$ to $10^{12}M_\odot$ (approximately $L_*$ galaxies at this redshift) using imaging data from the Cosmic Infrared Background Experiment (CIBER). A previous CIBER fluctuation analysis suggested that intra-halo light (IHL) contributes a significant portion of the near-infrared extragala… ▽ More We study the stellar halos of $0.2\lesssim z \lesssim 0.5$ galaxies with stellar masses spanning $M_*\sim 10^{10.5}$ to $10^{12}M_\odot$ (approximately $L_*$ galaxies at this redshift) using imaging data from the Cosmic Infrared Background Experiment (CIBER). A previous CIBER fluctuation analysis suggested that intra-halo light (IHL) contributes a significant portion of the near-infrared extragalactic background light (EBL), the integrated emission from all sources throughout cosmic history. In this work, we carry out a stacking analysis with a sample of $\sim$30,000 Sloan Digital Sky Survey (SDSS) photometric galaxies from CIBER images in two near-infrared bands (1.1 and 1.8 $μ$m) to directly probe the IHL associated with these galaxies. We stack galaxies in five sub-samples split by brightness, and detect an extended galaxy profile, beyond the instrument point spread function (PSF), derived by stacking stars. We jointly fit a model for the inherent galaxy light profile, plus large-scale one- and two-halo clustering to measure the extended galaxy IHL. We detect non-linear one-halo clustering in the 1.8 $μ$m band, at a level consistent with numerical simulations. Our results on the galaxy profile suggest that $\sim 50\%$ of the total galaxy light budget in our galaxy sample resides in the outskirts of the galaxies at $r > 10$ kpc. We describe this extended emission as IHL and and are able to study how this fraction evolves with cosmic time. These results are new in the near-infrared wavelength at the $L_*$ mass scale, and suggest that IHL has a significant contribution to the integrated galactic light, and to the amplitude of large-scale background fluctuations. △ Less

Submitted 21 September, 2021; v1 submitted 5 March, 2021; originally announced March 2021.

Comments: 29 pages, 17 figures, accepted by ApJ

Scalar and fermion on-shell amplitudes in generalized Higgs effective field theory

Authors: Ryo Nagai, Masaharu Tanabashi, Koji Tsumura, Yoshiki Uchida

Abstract: Beyond standard model (BSM) particles should be included in effective field theory in order to compute the scattering amplitudes involving these extra particles. We formulate an extension of Higgs effective field theory which contains arbitrary number of scalar and fermion fields with arbitrary electric and chromoelectric charges. The BSM Higgs sector is described by using the non-linear sigma mod… ▽ More Beyond standard model (BSM) particles should be included in effective field theory in order to compute the scattering amplitudes involving these extra particles. We formulate an extension of Higgs effective field theory which contains arbitrary number of scalar and fermion fields with arbitrary electric and chromoelectric charges. The BSM Higgs sector is described by using the non-linear sigma model in a manner consistent with the spontaneous electroweak symmetry breaking. The chiral order counting rule is arranged consistently with the loop expansion. The leading order Lagrangian is organized in accord with the chiral order counting rule. We use a geometrical language to describe the particle interactions. The parametrization redundancy in the effective Lagrangian is resolved by describing the on-shell scattering amplitudes only with the covariant quantities in the scalar/fermion field space. We introduce a useful coordinate (normal coordinate), which simplifies the computations of the on-shell amplitudes significantly. We show the high energy behaviors of the scattering amplitudes determine the "curvature tensors" in the scalar/fermion field space. The massive spinor-wavefunction formalism is shown to be useful in the computations of on-shell helicity amplitudes. △ Less

Submitted 8 June, 2021; v1 submitted 16 February, 2021; originally announced February 2021.

Comments: 34 pages, 5 figures, version accepted for publication in PRD, typos corrected

Report number: KYUSHU-HET-221

Journal ref: Phys. Rev. D 104, 015001 (2021)

Detectability of optical transients with timescales of sub-seconds

Authors: Ko Arimatsu, Kohji Tsumura, Fumihiko Usui, Takafumi Ootsubo, Jun-ichi Watanabe

Abstract: We search for optical transient sources with durations of $\sim 0.1$ to $\sim 1.3$ s using a dataset obtained in the Organized Autotelescopes for Serendipitous Event Survey (OASES) observation campaign. Since the OASES observations were carried out using two independent wide-field and high-cadence observation systems monitored the same field simultaneously, the obtained dataset provides a unique o… ▽ More We search for optical transient sources with durations of $\sim 0.1$ to $\sim 1.3$ s using a dataset obtained in the Organized Autotelescopes for Serendipitous Event Survey (OASES) observation campaign. Since the OASES observations were carried out using two independent wide-field and high-cadence observation systems monitored the same field simultaneously, the obtained dataset provides a unique opportunity to develop a robust detection method for sub-second optical transients. In the dataset of a selected field around the ecliptic and the Galactic plane, we find no astronomical event candidate that satisfies our detection criteria. From the non-detection result, we derive an upper limit on the event rate of sub-second transients around the ecliptic and the Galactic plane for the first time, obtaining $\sim 0.090$ and $\sim 0.38~{\rm hr^{-1}~deg^{-2}}$ for $m = 12$ and 13 Vmag, respectively. In addition, future prospects of the sub-second scale transient event surveys are discussed. △ Less

Submitted 7 January, 2021; originally announced January 2021.

Comments: 8 pages, 2 figures, accepted for publication in the Astronomical Journal

Search for U(1)$_{L_μ-L_τ}$ charged Dark Matter with neutrino telescope

Authors: Kento Asai, Shohei Okawa, Koji Tsumura

Abstract: We study a simple Dirac fermion dark matter model in U(1)$_{L_μ-L_τ}$ theory. The new light gauge boson $X$ plays important roles in both dark matter physics and the explanation for the muon $g-2$ anomaly. The observed dark matter relic density is realized by a large U(1)$_{L_μ-L_τ}$ charge without introducing a resonance effect of the $X$ boson. As a by-product of the model, characteristic neutri… ▽ More We study a simple Dirac fermion dark matter model in U(1)$_{L_μ-L_τ}$ theory. The new light gauge boson $X$ plays important roles in both dark matter physics and the explanation for the muon $g-2$ anomaly. The observed dark matter relic density is realized by a large U(1)$_{L_μ-L_τ}$ charge without introducing a resonance effect of the $X$ boson. As a by-product of the model, characteristic neutrino signatures from sub-GeV dark matter $ψ$ are predicted depending on the mass spectrum. We formulate the analysis of $ψ\barψ\to ν\barν$, and of $ψ\barψ\to XX$ followed by $X\toν\barν$, in a model independent way. The energy spectrum of neutrinos in the former process is monochromatic while in the latter process is bowl-shape. We also evaluate sensitivity at Super-Kamiokande and future Hyper-Kamiokande detectors. The analysis is finally applied to the U(1)$_{L_μ-L_τ}$ dark matter model. △ Less

Submitted 25 January, 2021; v1 submitted 5 November, 2020; originally announced November 2020.

Comments: 32 pages, 6 figures; v2: added references and comments, corrected the neutrino spectrum from secluded annihilation and corresponding plots, conclusion unchanged, version to be published in JHEP

Report number: KYUSHU-HET-217

Journal ref: JHEP 03 (2021) 047

Estimating survival probability using the terrestrial extinction history for the search for extraterrestrial life

Authors: Kohji Tsumura

Abstract: Several exoplanets have been discovered to date, and the next step is the search for extraterrestrial life. However, it is difficult to estimate the number of life-bearing exoplanets because our only template is based on life on Earth. In this paper, a new approach is introduced to estimate the probability that life on Earth has survived from birth to the present based on its terrestrial extinctio… ▽ More Several exoplanets have been discovered to date, and the next step is the search for extraterrestrial life. However, it is difficult to estimate the number of life-bearing exoplanets because our only template is based on life on Earth. In this paper, a new approach is introduced to estimate the probability that life on Earth has survived from birth to the present based on its terrestrial extinction history. A histogram of the extinction intensity during the Phanerozoic Eon is modeled effectively with a log-normal function, supporting the idea that terrestrial extinction is a random multiplicative process. Assuming that the fitted function is a probability density function of extinction intensity per unit time, the estimated survival probability of life on Earth is ~0.15 from the beginning of life to the present. This value can be a constraint on $f_i$ in the Drake equation, which contributes to estimating the number of life-bearing exoplanets. △ Less

Submitted 20 July, 2020; originally announced July 2020.

Comments: 11 pages, 3 figures, 1 table, accepted by Scientific Reports

Distributed Stabilization by Probability Control for Deterministic-Stochastic Large Scale Systems : Dissipativity Approach

Authors: Koji Tsumura, Binh Minh Nguyen, Hisaya Wakayama, Shinji Hara

Abstract: By using dissipativity approach, we establish the stability condition for the feedback connection of a deterministic dynamical system $Σ$ and a stochastic memoryless map $Ψ$. After that, we extend the result to the class of large scale systems in which: $Σ$ consists of many sub-systems; and $Ψ$ consists of many "stochastic actuators" and "probability controllers" that control the actuator's output… ▽ More By using dissipativity approach, we establish the stability condition for the feedback connection of a deterministic dynamical system $Σ$ and a stochastic memoryless map $Ψ$. After that, we extend the result to the class of large scale systems in which: $Σ$ consists of many sub-systems; and $Ψ$ consists of many "stochastic actuators" and "probability controllers" that control the actuator's output events. We will demonstrate the proposed approach by showing the design procedures to globally stabilize the manufacturing systems while locally balance the stock levels in any production process. △ Less

Submitted 6 May, 2020; originally announced May 2020.

Comments: 8 pages, 11 figures, submitted to IEEE CDC 2020

Scalegenesis and fermionic dark matters in the flatland scenario

Authors: Yu Hamada, Koji Tsumura, Masatoshi Yamada

Abstract: We propose an extension of the standard model with Majorana-type fermionic dark matters based on the flatland scenario where all scalar coupling constants, including scalar mass terms, vanish at the Planck scale, i.e. the scalar potential is flat above the Planck scale. This scenario could be compatible with the asymptotic safety paradigm for quantum gravity. We search the parameter space so that… ▽ More We propose an extension of the standard model with Majorana-type fermionic dark matters based on the flatland scenario where all scalar coupling constants, including scalar mass terms, vanish at the Planck scale, i.e. the scalar potential is flat above the Planck scale. This scenario could be compatible with the asymptotic safety paradigm for quantum gravity. We search the parameter space so that the model reproduces the observed values such as the Higgs mass, the electroweak vacuum and the relic abundance of dark matter. We also investigate the spin-independent elastic cross section for the Majorana fermions and a nucleon. It is shown that the Majorana fermions as dark matter candidates could be tested by dark matter direct detection experiments such as XENON, LUX and PandaX-II. We demonstrate that within the minimal setup compatible with the flatland scenario at the Planck scale or asymptotically safe quantum gravity, the extended model could have a strong predictability. △ Less

Submitted 6 May, 2020; v1 submitted 10 February, 2020; originally announced February 2020.

Comments: 23 pages, 9 figures, Version published in EPJC

Report number: KUNS-2786, KYUSHU-HET-208

Journal ref: Eur.Phys.J. C80 (2020) no.5, 368

Pseudo-Nambu-Goldstone dark matter from gauged $U(1)_{B-L}$ symmetry

Authors: Yoshihiko Abe, Takashi Toma, Koji Tsumura

Abstract: A pseudo-Nambu-Goldstone boson (pNGB) is an attractive candidate for dark matter since the current severe limits of dark matter direct detection experiments are naturally evaded by its nature. We construct a model with pNGB dark matter based on a {\it gauged} $U(1)_{B-L}$ symmetry, where no ad-hoc global symmetry is assumed. The model keeps natural suppression mechanism for the dark matter direct… ▽ More A pseudo-Nambu-Goldstone boson (pNGB) is an attractive candidate for dark matter since the current severe limits of dark matter direct detection experiments are naturally evaded by its nature. We construct a model with pNGB dark matter based on a {\it gauged} $U(1)_{B-L}$ symmetry, where no ad-hoc global symmetry is assumed. The model keeps natural suppression mechanism for the dark matter direct detection cross section. On the other hand, the pNGB can decay through the new high scale suppressed operators. We show that the pNGB has long enough lifetime to be a dark matter in the wide range of the parameter space of the model. The thermal relic abundance of pNGB dark matter can be fit with the observed value against the constraints on the dark matter decays from the cosmic-ray observations. △ Less

Submitted 27 April, 2020; v1 submitted 12 January, 2020; originally announced January 2020.

Comments: 17 pages, 3 figures, 1 table, version to appear in JHEP

Report number: KUNS-2782, KYUSHU-HET-203

QED background against atomic neutrino process with initial spatial phase

Authors: Minoru Tanaka, Koji Tsumura, Noboru Sasao, Satoshi Uetake, Motohiko Yoshimura

Abstract: Atomic deexcitation emitting a neutrino pair and a photon is expected to provide a novel method of neutrino physics if it is enhanced by quantum coherence in a macroscopic target. However, the same enhancement mechanism may also lead to a serious problem of enhanced QED background process. We show that the QED background can be suppressed enough in the photonic crystal waveguide by using the spati… ▽ More Atomic deexcitation emitting a neutrino pair and a photon is expected to provide a novel method of neutrino physics if it is enhanced by quantum coherence in a macroscopic target. However, the same enhancement mechanism may also lead to a serious problem of enhanced QED background process. We show that the QED background can be suppressed enough in the photonic crystal waveguide by using the spatial phase that is imprinted in the process of initial coherence generation in the target at excitation. △ Less

Submitted 5 December, 2019; originally announced December 2019.

Comments: 15 pages, 8 figures

Report number: OU-HET 1033, KYSHU-HET-202

Amateur telescopes discover a kilometre-sized Kuiper belt object from stellar occultation

Authors: K. Arimatsu, K. Tsumura, F. Usui, Y. Shinnaka, K. Ichikawa, T. Ootsubo, T. Kotani, T. Wada, K. Nagase, J. Watanabe

Abstract: Kuiper belt objects (KBOs) are thought to be the remnant of the early solar system, and their size distribution provides an opportunity to explore the formation and evolution of the outer solar system. In particular, the size distribution of kilometre-sized (radius = 1-10 km) KBO represents a signature of initial planetesimal sizes when planets form. These kilometre-sized KBOs are extremely faint,… ▽ More Kuiper belt objects (KBOs) are thought to be the remnant of the early solar system, and their size distribution provides an opportunity to explore the formation and evolution of the outer solar system. In particular, the size distribution of kilometre-sized (radius = 1-10 km) KBO represents a signature of initial planetesimal sizes when planets form. These kilometre-sized KBOs are extremely faint, and it is impossible to detect them directly. Instead, monitoring of stellar occultation events is one possible way to discover these small KBOs. Hitherto, however, there has been no observational evidence for the occultation events by KBOs with radii of 1-10 km. Here we report the first detection of a single occultation event candidate by a KBO with a radius of $\sim$1.3 km, which is simultaneously provided by two low-cost small telescopes coupled with commercial CMOS cameras. From this detection, we conclude that a surface number density of KBOs with radii exceeding $\sim 1.2$ km is $\sim 6 \times 10^5 \ {\rm deg^{-2}}$. This surface number density favours a theoretical size distribution model with an excess signature at a radius of 1-2 km. If this is a true detection, this implies that planetesimals before their runaway growth phase grow into kilometre-sized objects in the primordial outer solar system and remain as a major population of the present-day Kuiper belt. △ Less

Submitted 22 October, 2019; originally announced October 2019.

Comments: 23 pages, 10 figures, author final submission version, published in Nature Astronomy on 28 January 2019 (free version: https://rdcu.be/biPGW)

Journal ref: Nature Astronomy, 3, pages 301-306 (2019)

Large angular scale fluctuations of near infrared extragalactic background light based on the IRTS observations

Authors: Min Gyu Kim, Hyung Mok Lee, Woong-Seob Jeong, Kohji Tsumura, Hyungjong Seo, Masahiro Tanaka

Abstract: We measure the spatial fluctuations of the Near-Infrared Extragalactic Background Light (NIREBL) from 2$^{\circ}$ to 20$^{\circ}$ in angular scale at the 1.6 and 2.2 $μ$m using data obtained with Near-Infrared Spectrometer (NIRS) on board the Infrared Telescope in Space (IRTS). The brightness of the NIREBL is estimated by subtracting foreground components such as zodiacal light, diffuse Galactic l… ▽ More We measure the spatial fluctuations of the Near-Infrared Extragalactic Background Light (NIREBL) from 2$^{\circ}$ to 20$^{\circ}$ in angular scale at the 1.6 and 2.2 $μ$m using data obtained with Near-Infrared Spectrometer (NIRS) on board the Infrared Telescope in Space (IRTS). The brightness of the NIREBL is estimated by subtracting foreground components such as zodiacal light, diffuse Galactic light, and integrated star light from the observed sky. The foreground components are estimated using well-established models and archive data. The NIREBL fluctuations for the 1.6 and 2.2 $μ$m connect well toward the sub-degree scale measurements from previous studies. Overall, the fluctuations show a wide bump with a center at around 1$^{\circ}$ and the power decreases toward larger angular scales with nearly a single power-law spectrum (i.e. \textit{F($\sqrt{l(l+1)C_l/2π}$)} $\sim$ $θ^{-1}$) indicating that the large scale power is dominated by the random spatial distribution of the sources. After examining several known sources, contributors such as normal galaxies, high redshift objects, intra-halo light, and far-IR cosmic background, we conclude that the excess fluctuation at around the 1$^{\circ}$ scale cannot be explained by any of them. △ Less

Submitted 5 August, 2019; originally announced August 2019.

Fluctuation of the background sky in the Hubble Extremely Deep Field (XDF) and its origin

Authors: Toshio Matsumoto, Kohji Tsumura

Abstract: We performed a fluctuation analysis of the Hubble Extremely Deep Field (XDF) at four optical wavelength bands and found large fluctuations that are significantly brighter than those expected for ordinary galaxies. Good cross-correlations with flat spectra are found down to 0.2 arcsec, indicating the existence of a spatial structure even at the 0.2 arcsec scale. The detected auto and cross-correlat… ▽ More We performed a fluctuation analysis of the Hubble Extremely Deep Field (XDF) at four optical wavelength bands and found large fluctuations that are significantly brighter than those expected for ordinary galaxies. Good cross-correlations with flat spectra are found down to 0.2 arcsec, indicating the existence of a spatial structure even at the 0.2 arcsec scale. The detected auto and cross-correlations provide a lower limit of 24 nW m$^{-2}$ sr$^{-1}$ for the absolute sky brightness at 700-900 nm, which is consistent with previous observations. We searched for candidate objects to explain the detected large fluctuation using the catalog of the Hubble Ultra Deep Field (UDF), and found that the surface number density of faint compact objects (FCOs) rapidly increases toward the faint end. Radial profiles of FCOs are indistinguishable from the PSF, and the effective radius based on de Vaucouleur's law is estimated to be smaller than 0.02 arcsec. The SEDs of FCOs follow a power law at optical wavelengths, but show greater emission and structure at $λ$ > 1 $μ$m. Assuming that the FCOs are the cause of the excess brightness and fluctuations, the faint magnitude limit is 34.9 mag for the F775W band, and the surface number density reaches $2.6 \times 10^3$ (arcsec)$^{-2}$. Recent gamma-ray observations require that the redshift of FCOs must be less than 0.1, if FCOs are the origin of the excess optical and infrared background. Assuming that FCOs consist of missing baryons, the mass and luminosity of a single FCO range from $10^{2}$ to 1$0^{3}$ solar units, and mass-to-luminosity ratio is significantly lower than 1.0 solar unit. The maximum effective radius of an FCO is 4.7 pc. These results and the good correlation between near-infrared and X-ray background indicate that FCOs could be powered by the gravitational energy associated with black holes. △ Less

Submitted 3 June, 2019; originally announced June 2019.

Comments: 37 pages, 21 figures, accepted to PASJ

A $μ$-$τ$-philic scalar doublet under $Z_n$ flavor symmetry

Authors: Yoshihiko Abe, Takashi Toma, Koji Tsumura

Abstract: We propose a minimal model which accommodates the long-standing anomaly of muon magnetic moment based on abelian discrete flavor symmetries. The standard model is extended by scalar doublets charged under a $Z_n$ lepton flavor symmetry. In these models, a large contribution to the muon magnetic moment can be obtained by the chirality enhancement from new scalar mediated diagrams without conflictin… ▽ More We propose a minimal model which accommodates the long-standing anomaly of muon magnetic moment based on abelian discrete flavor symmetries. The standard model is extended by scalar doublets charged under a $Z_n$ lepton flavor symmetry. In these models, a large contribution to the muon magnetic moment can be obtained by the chirality enhancement from new scalar mediated diagrams without conflicting with the flavor symmetry. Thanks to the lepton flavor symmetry, these models automatically forbid lepton flavor violation. The minimal model is based on $Z_4$ symmetry with only one extra scalar doublet. In this model, we show that the parameter space favored by the muon $g-2$ can easily be consistent with experimental constraints and theoretical bounds such as the electroweak precision tests, lepton universality, potential stability condition and triviality bound as well as the LHC direct search mass bound. The new contributions to the muon electric dipole moment and the Higgs decay into $γγ$ can be indirect signals of the model. △ Less

Submitted 22 June, 2019; v1 submitted 24 April, 2019; originally announced April 2019.

Comments: 22 pages, 8 figures, 1 table, version to appear in JHEP

Report number: KUNS-2760

Journal ref: JHEP 06 (2019) 142

Symmetry and geometry in generalized Higgs effective field theory -- Finiteness of oblique corrections v.s. perturbative unitarity

Authors: Ryo Nagai, Masaharu Tanabashi, Koji Tsumura, Yoshiki Uchida

Abstract: We formulate a generalization of Higgs effective field theory (HEFT) including arbitrary number of extra neutral and charged Higgs bosons (generalized HEFT, GHEFT) to describe non-minimal electroweak symmetry breaking models. Using the geometrical form of the GHEFT Lagrangian, which can be regarded as a nonlinear sigma model on a scalar manifold, it is shown that the scalar boson scattering amplit… ▽ More We formulate a generalization of Higgs effective field theory (HEFT) including arbitrary number of extra neutral and charged Higgs bosons (generalized HEFT, GHEFT) to describe non-minimal electroweak symmetry breaking models. Using the geometrical form of the GHEFT Lagrangian, which can be regarded as a nonlinear sigma model on a scalar manifold, it is shown that the scalar boson scattering amplitudes are described in terms of the Riemann curvature tensor (geometry) of the scalar manifold and the covariant derivatives of the potential. The coefficients of the one-loop divergent terms in the oblique correction parameters S and U can also be written in terms of the Killing vectors (symmetry) and the Riemann curvature tensor (geometry). It is found that perturbative unitarity of the scattering amplitudes involving the Higgs bosons and the longitudinal gauge bosons demands the flatness of the scalar manifold. The relationship between the finiteness of the electroweak oblique corrections and perturbative unitarity of the scattering amplitudes is also clarified in this language: we verify that once the tree-level unitarity is ensured, then the one-loop finiteness of the oblique correction parameters S and U is automatically guaranteed. △ Less

Submitted 13 September, 2019; v1 submitted 16 April, 2019; originally announced April 2019.

Comments: 55 pages; an appendix on symmetry-geometry dictionary added; version accepted for publication in PRD

Report number: KUNS-2755

Journal ref: Phys. Rev. D 100, 075020 (2019)

Minimal Gauged U(1)$_{L_α- L_β}$ Models Driven into a Corner

Authors: Kento Asai, Koichi Hamaguchi, Natsumi Nagata, Shih-Yen Tseng, Koji Tsumura

Abstract: It is well known that the differences between the lepton numbers can be gauged with the Standard Model matter content. Such extended gauge theories, dubbed as the gauged U(1)$_{L_α- L_β}$ models, have been widely discussed so far as potential candidates for physics beyond the Standard Model. In this work, we study the minimal versions of these gauge theories, where three right-handed neutrinos as… ▽ More It is well known that the differences between the lepton numbers can be gauged with the Standard Model matter content. Such extended gauge theories, dubbed as the gauged U(1)$_{L_α- L_β}$ models, have been widely discussed so far as potential candidates for physics beyond the Standard Model. In this work, we study the minimal versions of these gauge theories, where three right-handed neutrinos as well as a single U(1)$_{L_α- L_β}$ symmetry breaking Higgs field---an SU(2)$_L$ singlet or doublet---are introduced. In these minimal models, the neutrino mass terms are constrained by the gauge symmetry, which result in the two-zero texture or two-zero minor structure of neutrino mass matrices. Such restrictive forms of neutrino mass matrices lead to non-trivial predictions for the neutrino oscillation parameters as well as the size of the mass eigenvalues. We find that due to this restriction the minimal gauged U(1)$_{L_α- L_β}$ models are either incompatible with the observed values of the neutrino parameters or in strong tension with the Planck 2018 limit on the sum of the neutrino masses. Only the U(1)$_{L_μ-L_τ}$ model with an SU(2)$_L$ singlet U(1)$_{L_μ-L_τ}$-breaking field barely evades the limit, which can be tested in the future neutrino experiments. △ Less

Submitted 28 March, 2019; v1 submitted 19 November, 2018; originally announced November 2018.

Comments: 25 pages, 7 figures

Report number: UT-18-28, IPMU18-0191, KUNS-2740

Journal ref: Phys. Rev. D 99, 055029 (2019)

Precision electroweak shift of muonium hyperfine splitting

Authors: T. Asaka, M. Tanaka, K. Tsumura, M. Yoshimura

Abstract: Electroweak second order shifts of muonium ($μ^+e^-$ bound state) energy levels are calculated for the first time. Calculation starts from on-shell one-loop elastic $μ^+ e^-$ scattering amplitudes in the center of mass frame, proceed to renormalization and to derivation of muonium matrix elements by using the momentum space wave functions. This is a reliable method unlike the unjustified four-Ferm… ▽ More Electroweak second order shifts of muonium ($μ^+e^-$ bound state) energy levels are calculated for the first time. Calculation starts from on-shell one-loop elastic $μ^+ e^-$ scattering amplitudes in the center of mass frame, proceed to renormalization and to derivation of muonium matrix elements by using the momentum space wave functions. This is a reliable method unlike the unjustified four-Fermi approximation in the literature. Corrections of order $αG_F$ (with $α\sim 1/137$ the fine structure constant and $G_F$ the Fermi constant) and of order $αG_F /(m_Z a_B)$ (with $m_Z$ the Z boson mass and $a_B$ the Bohr radius) are derived from three classes of Feynman diagrams, Z self-energy, vertex and box diagrams. The ground state muonium hyperfine splitting is given in terms of the only experimentally unknown parameter, the smallest neutrino mass. It is however found that the neutrino mass dependence is very weak, making its detection difficult. △ Less

Submitted 12 October, 2018; originally announced October 2018.

Comments: 6 pages, 3 figures

Zodiacal Light Beyond Earth Orbit Observed with Pioneer 10

Authors: T. Matsumoto, K. Tsumura, Y. Matsuoka, J. Pyo

Abstract: We reanalyze the Imaging Photopolarimeter data from Pioneer 10 to study the zodiacal light in the B and R bands beyond Earth orbit, applying an improved method to subtract integrated star light (ISL) and diffuse Galactic light (DGL). We found that there exists a significant instrumental offset, making it difficult to examine the absolute sky brightness. Instead, we analyzed the differential bright… ▽ More We reanalyze the Imaging Photopolarimeter data from Pioneer 10 to study the zodiacal light in the B and R bands beyond Earth orbit, applying an improved method to subtract integrated star light (ISL) and diffuse Galactic light (DGL). We found that there exists a significant instrumental offset, making it difficult to examine the absolute sky brightness. Instead, we analyzed the differential brightness, i.e., the difference in sky brightness from the average at high ecliptic latitude, and compared with that expected from the model zodiacal light. At a heliocentric distance of r<2 au, we found a fairly good correlation between the J-band model zodiacal light and the residual sky brightness after subtracting the ISL and DGL. The reflectances of the interplanetary dust derived from the correlation study are marginally consistent with previous works. The zodiacal light is not significantly detectable at r>3 au, as previously reported. However, a clear discrepancy from the model is found at r=2.94 au which indicates the existence of a local dust cloud produced by the collision of asteroids or dust trail from active asteroids (or main-belt comets). Our result confirms that the main component of the zodiacal light (smooth cloud) is consistent with the model even beyond the earth orbit, which justifies the detection of the extragalactic background light after subtracting the zodiacal light based on the model. △ Less

Submitted 11 August, 2018; originally announced August 2018.

Comments: 13 pages, 8 figures

MSC Class: 85A04 (Primary); 85A99 (Secondary)

Journal ref: The Astronomical Journal, 156:86 (6pp), 2018 September

Is the Infrared Background Excess Explained by the Isotropic Zodiacal Light from the Outer Solar System?

Authors: Kohji Tsumura

Abstract: This paper investigates whether an isotropic zodiacal light from the outer Solar system can account for the detected background excess in near-infrared. Assuming that interplanetary dust particles are distributed in a thin spherical shell at the outer Solar system (>200 AU), thermal emission from such cold (<30 K) dust in the shell has a peak at far-infrared (~100 microns). By comparing the calcul… ▽ More This paper investigates whether an isotropic zodiacal light from the outer Solar system can account for the detected background excess in near-infrared. Assuming that interplanetary dust particles are distributed in a thin spherical shell at the outer Solar system (>200 AU), thermal emission from such cold (<30 K) dust in the shell has a peak at far-infrared (~100 microns). By comparing the calculated thermal emission from the dust shell with the observed background emissions at far-infrared, permissible dust amount in the outer Solar system is obtained. Even if the maximum dust amount is assumed, the isotropic zodiacal light as the reflected sunlight from the dust shell at the outer Solar system cannot explain the detected background excess at near-infrared. △ Less

Submitted 10 August, 2018; originally announced August 2018.

Comments: 6 pages, 2 figures, accepted by PASJ

Charged scalars confronting neutrino mass and muon g-2 anomaly

Authors: Nabarun Chakrabarty, Cheng-Wei Chiang, Takahiro Ohata, Koji Tsumura

Abstract: The present work introduces two possible extensions of the Standard Model Higgs sector. In the first case, the Zee-Babu type model for the generation of neutrino mass is augmented with a scalar triplet and additional singly charged scalar singlets. The second scenario, on the other hand, generalizes the Type-II seesaw model by replicating the number of the scalar triplets. A $\mathbb{Z}_3$ symmetr… ▽ More The present work introduces two possible extensions of the Standard Model Higgs sector. In the first case, the Zee-Babu type model for the generation of neutrino mass is augmented with a scalar triplet and additional singly charged scalar singlets. The second scenario, on the other hand, generalizes the Type-II seesaw model by replicating the number of the scalar triplets. A $\mathbb{Z}_3$ symmetry is imposed in case of both the scenarios, but, allowed to be violated by terms of mass dimension two and three for generating neutrino masses and mixings. We examine how the models so introduced can explain the experimental observation on the muon anomalous magnetic moment. We estimate the two-loop contribution to neutrino mass induced by the scalar triplet, in addition to what comes from the doubly charged singlet in the usual Zee-Babu framework, in the first model. On the other hand, the neutrino mass arises in the usual Type-II fashion in the second model. In addition, the role of the $\mathbb{Z}_3$ symmetry in suppressing lepton flavor violation is also elucidated. △ Less

Submitted 21 July, 2018; originally announced July 2018.

Comments: 4 tables, 14 captioned figures

MIRIS observation of near-infrared diffuse Galactic light

Authors: Y. Onishi, K. Sano, S. Matsuura, W. -S. Jeong, J. Pyo, I. -J. Kim, H. J. Seo, W. Han, D. -H. Lee, B. Moon, W. -K. Park, Y. Park, M. G. Kim, T. Matsumoto, H. Matsuhara, T. Nakagawa, K. Tsumura, M. Shirahata, T. Arai, N. Ienaka

Abstract: We report near-infrared (IR) observations of high Galactic latitude clouds to investigate diffuse Galactic light (DGL), which is starlight scattered by interstellar dust grains. The observations were performed at $1.1$ and $1.6\,\rm{μm}$ with a wide-field camera instrument, the Multi-purpose Infra-Red Imaging System (MIRIS) onboard the Korean satellite STSAT-3. The DGL brightness is measured by co… ▽ More We report near-infrared (IR) observations of high Galactic latitude clouds to investigate diffuse Galactic light (DGL), which is starlight scattered by interstellar dust grains. The observations were performed at $1.1$ and $1.6\,\rm{μm}$ with a wide-field camera instrument, the Multi-purpose Infra-Red Imaging System (MIRIS) onboard the Korean satellite STSAT-3. The DGL brightness is measured by correlating the near-IR images with a far-IR $100\,\rm{μm}$ map of interstellar dust thermal emission. The wide-field observation of DGL provides the most accurate DGL measurement achieved to date. We also find a linear correlation between optical and near-IR DGL in the MBM32 field. To study interstellar dust properties in MBM32, we adopt recent dust models with or without $\rm{μm}$-sized very large grains and predict the DGL spectra, taking into account reddening effect of interstellar radiation field. The result shows that observed color of the near-IR DGL is closer to the model spectra without very large grains. This may imply that dust growth in the observed MBM32 field is not active owing to its low density of interstellar medium. △ Less

Submitted 22 June, 2018; originally announced June 2018.

Comments: 14 pages, 13 figures, accepted for PASJ

Unusual Superconducting Proximity Effect in Magnetically Doped Topological Josephson Junctions

Authors: Rikizo Yano, Masao Koyanagi, Hiromi Kashiwaya, Kohei Tsumura, Hishiro T. Hirose, Takao Sasagawa, Yasuhiro Asano, Satoshi Kashiwaya

Abstract: The transport properties of a topological Josephson junction fabricated from a magnetically doped topological insulator (TI) were investigated. The conductance spectra of the Nb/Fe-Bi$_2$Te$_2$Se/Nb junction below 1 K showed an unusual trident-shaped zero-bias conductance peak with a tiny peak width of $\sim$ 6 $μ$V. The central peak of the trident peak presents the dc-Josephson current, and the s… ▽ More The transport properties of a topological Josephson junction fabricated from a magnetically doped topological insulator (TI) were investigated. The conductance spectra of the Nb/Fe-Bi$_2$Te$_2$Se/Nb junction below 1 K showed an unusual trident-shaped zero-bias conductance peak with a tiny peak width of $\sim$ 6 $μ$V. The central peak of the trident peak presents the dc-Josephson current, and the side peaks may reflect an induced unconventional Cooper pairing. Additionally, the critical currents followed inverse to temperature, which may also reflect the presence of an unconventional proximity effect. Furthermore, microwave irradiation derived a drastic change in the conductance spectra from the peak structure into oscillatory ones, a hallmark of the ac-Josephson supercurrent. The current-phase relation of the ac-Josephson effect under high power radiofrequency-irradiation was found to be 4$π$-periodic. The results suggest that the junction based on magnetically doped 3D TIs may realize an unconventional Cooper pairing, thus enabling access to the basic physics of Majorana bound states and unconventional superconductivity. △ Less

Submitted 12 February, 2020; v1 submitted 26 May, 2018; originally announced May 2018.

Comments: 19 pages, 6 figures

Journal ref: J. Phys. Soc. Jpn. 89, 034702 (2020)

Syndetic Extension of Baryon and Lepton Numbers: Proton Decay and Long-Lived Dark Matter

Authors: Ernest Ma, Koji Tsumura

Abstract: The well-known baryon and lepton numbers of the standard model of quarks and leptons are extended to include new fermions and bosons in a simple structure with several essential features. The usual heavy right-handed neutrino singlets (for neutrino mass and leptogenesis) are related to the axion which solves the strong CP problem. At the same time, baryon number is broken softly, allowing the prot… ▽ More The well-known baryon and lepton numbers of the standard model of quarks and leptons are extended to include new fermions and bosons in a simple structure with several essential features. The usual heavy right-handed neutrino singlets (for neutrino mass and leptogenesis) are related to the axion which solves the strong CP problem. At the same time, baryon number is broken softly, allowing the proton to decay. Associated with this breaking, a long-lived dark-matter candidate (called the pseudo-sakharon) emerges. This new insight connects proton decay to a new component of dark matter. △ Less

Submitted 14 May, 2018; originally announced May 2018.

Comments: 10 pages, 2 figures

Report number: KUNS-2721, UCRHEP-T590

Journal ref: Phys. Rev. D 98, 035037 (2018)

Spitzer Observations of the North Ecliptic Pole

Authors: H. Nayyeri, N. Ghotbi, A. Cooray, J. Bock, D. L. Clements, M. Im, M. G. Kim, P. Korngut, A. Lanz, H. M. Lee, D. H. Lee, M. Malkan, H. Matsuhara, T. Matsumoto, S. Matsuura, U. W. Nam, C. Pearson, S. Serjeant, J. Smidt, K. Tsumura, T. Wada, M. Zemcov

Abstract: We present a photometric catalog for Spitzer Space Telescope warm mission observations of the North Ecliptic Pole (NEP; centered at $\rm R.A.=18^h00^m00^s$, $\rm Decl.=66^d33^m38^s.552$). The observations are conducted with IRAC in 3.6 $μ$m and 4.5 $μ$m bands over an area of 7.04 deg$^2$ reaching 1$σ$ depths of 1.29 $μ$Jy and 0.79 $μ$Jy in the 3.6 $μ$m and 4.5 $μ$m bands respectively. The photomet… ▽ More We present a photometric catalog for Spitzer Space Telescope warm mission observations of the North Ecliptic Pole (NEP; centered at $\rm R.A.=18^h00^m00^s$, $\rm Decl.=66^d33^m38^s.552$). The observations are conducted with IRAC in 3.6 $μ$m and 4.5 $μ$m bands over an area of 7.04 deg$^2$ reaching 1$σ$ depths of 1.29 $μ$Jy and 0.79 $μ$Jy in the 3.6 $μ$m and 4.5 $μ$m bands respectively. The photometric catalog contains 380,858 sources with 3.6 $μ$m and 4.5 $μ$m band photometry over the full-depth NEP mosaic. Point source completeness simulations show that the catalog is 80% complete down to 19.7 AB. The accompanying catalog can be utilized in constraining the physical properties of extra-galactic objects, studying the AGN population, measuring the infrared colors of stellar objects, and studying the extra-galactic infrared background light. △ Less

Submitted 4 December, 2017; originally announced December 2017.

Comments: 10 pages, 11 figures and 3 tables. Accepted to the ApJS

Model with a gauged lepton flavor SU(2) symmetry

Authors: Cheng-Wei Chiang, Koji Tsumura

Abstract: We propose a model having a gauged $SU(2)$ symmetry associated with the second and third generations of leptons, dubbed $SU(2)_{μτ}$, of which $U(1)_{L_μ-L_τ}$ is an Abelian subgroup. In addition to the Standard Model fields, we introduce two types of scalar fields. One exotic scalar field is an $SU(2)_{μτ}$ doublet and SM singlet that develops a nonzero vacuum expectation value at presumably mult… ▽ More We propose a model having a gauged $SU(2)$ symmetry associated with the second and third generations of leptons, dubbed $SU(2)_{μτ}$, of which $U(1)_{L_μ-L_τ}$ is an Abelian subgroup. In addition to the Standard Model fields, we introduce two types of scalar fields. One exotic scalar field is an $SU(2)_{μτ}$ doublet and SM singlet that develops a nonzero vacuum expectation value at presumably multi-TeV scale to completely break the $SU(2)_{μτ}$ symmetry, rendering three massive gauge bosons. At the same time, the other exotic scalar field, carrying electroweak as well as $SU(2)_{μτ}$ charges, is induced to have a nonzero vacuum expectation value as well and breaks mass degeneracy between the muon and tau. We examine how the new particles in the model contribute to the muon anomalous magnetic moment in the parameter space compliant with the Michel decays of tau. △ Less

Submitted 14 May, 2018; v1 submitted 2 December, 2017; originally announced December 2017.

Comments: 21 pages, 13 figures

Report number: KUNS-2707

Coexistence of superconductivity and charge-density wave in the quasi-one-dimensional material HfTe3

Authors: Saleem J. Denholme, Akinori Yukawa, Kohei Tsumura, Masanori Nagao, Ryuji Tamura, Satoshi Watauchi, Isao Tanaka, Hideaki Takayanagi, Nobuaki Miyakawa

Abstract: We present the first experimental evidence for metallicity, superconductivity (SC) and the co-existence of charge density waves (CDW) in the quasi-one-dimensional material HfTe3. The existence of such phenomena is a typical characteristic of the transition metal chalcogenides however, without the application of hydrostatic pressure/chemical doping, it is rare for a material to exhibit the co-exist… ▽ More We present the first experimental evidence for metallicity, superconductivity (SC) and the co-existence of charge density waves (CDW) in the quasi-one-dimensional material HfTe3. The existence of such phenomena is a typical characteristic of the transition metal chalcogenides however, without the application of hydrostatic pressure/chemical doping, it is rare for a material to exhibit the co-existence of both states. Materials such as HfTe3 can therefore provide us with a unique insight into the relationship between these multiple ordered states. By improving on the original synthesis conditions, we have successfully synthesised single phase HfTe3 and confirmed the resultant structure by performing Rietveld refinement. Using low temperature resistivity measurements, we provide the first experimental evidence of SC at ~1.4 K as well as a resistive anomaly indicative of a CDW formation at ~82 K. By the application of hydrostatic-pressure, the resistivity anomaly shifts to higher temperature. The results show that HfTe3 is a promising new material to help study the relationship between SC and CDW. △ Less

Submitted 28 November, 2017; originally announced November 2017.

Comments: 9 pages, 4 figures, includes supplementary information

Journal ref: Scientific Reports 7, Article number: 45217 (2017)