Showing 1–49 of 49 results for author: Conrad, J

Direct Measurement of the $^{212}\mathrm{Pb}$ and $^{214}\mathrm{Pb}$ $β$ Decay Branching Ratios with the XENONnT Experiment

Authors: E. Aprile, J. Aalbers, K. Abe, M. Abu Rmeileh, M. Adrover, S. Ahmed Maouloud, L. Althueser, B. Andrieu, E. Angelino, D. Antón Martin, S. R. Armbruster, F. Arneodo, L. Baudis, M. Bazyk, V. Beligotti, L. Bellagamba, R. Biondi, A. Bismark, K. Boese, R. M. Braun, G. Bruni, R. Budnik, C. Cai, C. Capelli, J. M. R. Cardoso , et al. (156 additional authors not shown)

Abstract: We present precision measurements of $^{212}\mathrm{Pb}$ and $^{214}\mathrm{Pb}$ $β$ decay branching ratios using $^{220}\mathrm{Rn}$ and $^{222}\mathrm{Rn}$ calibration data from the XENONnT detector, a dual-phase liquid xenon time projection chamber. Characterizing these isotopes is critical, as they lead to significant low-energy backgrounds in rare-event searches. We report ground-state branch… ▽ More We present precision measurements of $^{212}\mathrm{Pb}$ and $^{214}\mathrm{Pb}$ $β$ decay branching ratios using $^{220}\mathrm{Rn}$ and $^{222}\mathrm{Rn}$ calibration data from the XENONnT detector, a dual-phase liquid xenon time projection chamber. Characterizing these isotopes is critical, as they lead to significant low-energy backgrounds in rare-event searches. We report ground-state branching ratios of $(14.75 \pm 0.20(\mathrm{stat}) ^{+0.14}_{-0.40}(\mathrm{sys}))\%$ for $^{212}\mathrm{Pb}$ and $(9.8 \pm 0.3(\mathrm{stat}) ^{+0.8}_{-0.2}(\mathrm{sys}))\%$ for $^{214}\mathrm{Pb}$, providing the most precise direct measurements of these transitions to date. These results contribute to enhancing background modeling for dark matter and neutrino experiments, improving sensitivity to solar neutrinos and physics beyond the Standard Model. △ Less

Submitted 18 June, 2026; v1 submitted 16 June, 2026; originally announced June 2026.

From Beam to Bedside: Reinforcing Domestic Supply of $^{99}$Mo/$^{99m}$Tc using Novel High-Current D+ Cyclotrons for Compact Neutron Generation and $^{99}$Mo Production

Authors: Jarrett Moon, Daniel Winklehner, Jose Alonso, Claire Huchthausen, David McClain, Janet Conrad

Abstract: Technetium-99m ($^{99m}$Tc) is essential to more than 16 million diagnostic procedures performed annually in the United States. It is typically acquired on-site from generators containing $^{99}$Mo, in turn produced at nuclear reactor facilities. This supply chain involves multiple points of vulnerability, which can lead to shortages and delays with potentially negative patient outcomes. We report… ▽ More Technetium-99m ($^{99m}$Tc) is essential to more than 16 million diagnostic procedures performed annually in the United States. It is typically acquired on-site from generators containing $^{99}$Mo, in turn produced at nuclear reactor facilities. This supply chain involves multiple points of vulnerability, which can lead to shortages and delays with potentially negative patient outcomes. We report on the development of a new family of cyclotrons originally designed for the IsoDAR neutrino experiment, capable of operating at much higher current than typical cyclotrons. When operated with deuterons at 1.5 MeV/amu and an anticipated continuous beam current of 5 mA, simulations project that such a system would yield $\sim$10$^{13}$ neutrons per second using a thin beryllium target. This neutron yield is sufficient, in principle, to support $^{99}$Mo production without the use of highly enriched uranium or reliance on foreign reactors. Simulations and conceptual design studies suggest that the system's beam dynamics could make it a viable pathway toward decentralized, hospital-based isotope generation. The relatively low energy of the deuterons minimizes activation and safety concerns. This work presents the physics motivation, technical design considerations, and projected neutron yields, outlining a pathway from a neutrino-physics prototype to a biomedical isotope production platform. △ Less

Submitted 4 March, 2026; v1 submitted 28 January, 2026; originally announced January 2026.

First Measurement of $π^+$-Ar and $p$-Ar Total Inelastic Cross Sections in the Sub-GeV Energy Regime with ProtoDUNE-SP Data

Authors: DUNE Collaboration, S. Abbaslu, F. Abd Alrahman, A. Abed Abud, R. Acciarri, L. P. Accorsi, M. A. Acero, M. R. Adames, G. Adamov, M. Adamowski, C. Adriano, F. Akbar, F. Alemanno, N. S. Alex, L. Aliaga Soplin, K. Allison, M. Alrashed, A. Alton, R. Alvarez, T. Alves, A. Aman, H. Amar, P. Amedo, J. Anderson, D. A. Andrade , et al. (1328 additional authors not shown)

Abstract: The ProtoDUNE-SP detector, a kiloton-scale prototype for the Deep Underground Neutrino Experiment (DUNE) far detector, is the largest liquid argon time projection chamber built to date. Operated at CERN from 2018 to 2020, it collected both cosmic-ray data and a beam consisting of positively-charged particles with discrete momentum settings across a range of 0.3 GeV/$c$ to 7 GeV/$c$. In this letter… ▽ More The ProtoDUNE-SP detector, a kiloton-scale prototype for the Deep Underground Neutrino Experiment (DUNE) far detector, is the largest liquid argon time projection chamber built to date. Operated at CERN from 2018 to 2020, it collected both cosmic-ray data and a beam consisting of positively-charged particles with discrete momentum settings across a range of 0.3 GeV/$c$ to 7 GeV/$c$. In this letter, we report the total inelastic cross section measurements for $π^+$--Ar and $p$--Ar interactions using selected $π^+$ and proton samples from the 1 GeV/$c$ beam data, spanning kinetic energies of 500--900~MeV and below 450~MeV, respectively. These energy ranges are directly relevant to hadrons produced in DUNE. The measured cross sections are consistent with predictions and provide a dataset that was previously unavailable for argon targets. These measurements are essential for constraining neutrino-argon interaction models and achieving the precision physics goals of the upcoming DUNE experiment. △ Less

Submitted 26 May, 2026; v1 submitted 14 November, 2025; originally announced November 2025.

Report number: FERMILAB-PUB-25-0814-LBNF, CERN-EP-2025-266

Spectral Measurement of the $^{214}$Bi beta-decay to the $^{214}$Po Ground State with XENONnT

Authors: E. Aprile, J. Aalbers, K. Abe, M. Adrover, S. Ahmed Maouloud, L. Althueser, B. Andrieu, E. Angelino, D. Antón Martin, S. R. Armbruster, F. Arneodo, L. Baudis, M. Bazyk, L. Bellagamba, R. Biondi, A. Bismark, K. Boese, R. M. Braun, A. Brown, G. Bruno, R. Budnik, C. Cai, C. Capelli, J. M. R. Cardoso, A. P. Cimental Chávez , et al. (148 additional authors not shown)

Abstract: We report the measurement of the $^{214}$Bi beta-decay spectrum to the ground state of $^{214}$Po using the XENONnT detector. This decay is classified as first-forbidden non-unique, for which theoretical predictions require detailed nuclear structure modeling. A dedicated identification algorithm isolates a high-purity sample of ground-state beta-decays, explicitly excluding events with associated… ▽ More We report the measurement of the $^{214}$Bi beta-decay spectrum to the ground state of $^{214}$Po using the XENONnT detector. This decay is classified as first-forbidden non-unique, for which theoretical predictions require detailed nuclear structure modeling. A dedicated identification algorithm isolates a high-purity sample of ground-state beta-decays, explicitly excluding events with associated gamma-rays emission. By comparing the measured spectrum, which covers energies up to 3.27 MeV, with several nuclear models, we find that the prediction based on the conserved vector current (CVC) hypothesis provides the best description of the data. Using this dataset, we additionally derive charge and light yield curves for electronic recoils, extending detector response modeling up to the MeV scale. △ Less

Submitted 6 October, 2025; originally announced October 2025.

IsoDAR@Yemilab: Preliminary Design Report -- Volume II: Medium Energy Beam Transport, Neutrino Source, and Shielding

Authors: Joshua Spitz, Jose R. Alonso, Jon Ameel, Roger Barlow, Larry Bartoszek, Adriana Bungau, Michael H. Shaevitz, Erik A. Voirin, Daniel Winklehner, Janet M. Conrad, Samuel J. Engebretson, Jarrett Moon, Eleanor Winkler, Andreas Adelmann, Spencer N. Axani, William A. Barletta, Luciano Calabretta, Pedro Calvo, Georgia Karagiorgi, Conceptión Oliver, Andrew Chan, Emilie Lavoie-Ingram

Abstract: This Preliminary Design Report (PDR) describes the IsoDAR electron-antineutrino source in two volumes which are mostly site-independent and describe the cyclotron driver providing a 60 MeV, 10 mA proton beam (Volume I); and the medium energy beam transport line (MEBT) and target (this Volume). The IsoDAR driver and target will produce about $1.15\cdot10^{23}$ electron-antineutrinos over five calen… ▽ More This Preliminary Design Report (PDR) describes the IsoDAR electron-antineutrino source in two volumes which are mostly site-independent and describe the cyclotron driver providing a 60 MeV, 10 mA proton beam (Volume I); and the medium energy beam transport line (MEBT) and target (this Volume). The IsoDAR driver and target will produce about $1.15\cdot10^{23}$ electron-antineutrinos over five calendar years. Paired with a kton-scale liquid scintillator detector, this will enable a broad particle physics program including searches for new symmetries, new interactions and new particles. Here in Volume II, we describe the medium energy beam transport line, the antineutrino source beam-target and surrounding sleeve, shielding, and plans for monitoring and installation. △ Less

Submitted 15 August, 2025; originally announced August 2025.

Challenging Spontaneous Quantum Collapse with XENONnT

Authors: E. Aprile, J. Aalbers, K. Abe, S. Ahmed Maouloud, L. Althueser, B. Andrieu, E. Angelino, D. Antón Martin, S. R. Armbruster, F. Arneodo, L. Baudis, M. Bazyk, L. Bellagamba, R. Biondi, A. Bismark, K. Boese, A. Brown, G. Bruno, R. Budnik, C. Cai, C. Capelli, J. M. R. Cardoso, A. P. Cimental Chávez, A. P. Colijn, J. Conrad , et al. (152 additional authors not shown)

Abstract: We report on the search for X-ray radiation as predicted from dynamical quantum collapse with low-energy electronic recoil data in the energy range of 1-140 keV from the first science run of the XENONnT dark matter detector. Spontaneous radiation is an unavoidable effect of dynamical collapse models, which were introduced as a possible solution to the long-standing measurement problem in quantum m… ▽ More We report on the search for X-ray radiation as predicted from dynamical quantum collapse with low-energy electronic recoil data in the energy range of 1-140 keV from the first science run of the XENONnT dark matter detector. Spontaneous radiation is an unavoidable effect of dynamical collapse models, which were introduced as a possible solution to the long-standing measurement problem in quantum mechanics. The analysis utilizes a model that for the first time accounts for cancellation effects in the emitted spectrum, which arise in the X-ray range due to the opposing electron-proton charges in xenon atoms. New world-leading limits on the free parameters of the Markovian continuous spontaneous localization and Diósi-Penrose models are set, improving previous best constraints by two orders of magnitude and a factor of five, respectively. The original values proposed for the strength and the correlation length of the continuous spontaneous localization model are excluded experimentally for the first time. △ Less

Submitted 24 March, 2026; v1 submitted 5 June, 2025; originally announced June 2025.

Comments: 7 pages, 3 figures

Journal ref: Phys. Rev. Lett. 136, 120201 (2026)

Neutrinoless Double Beta Decay Sensitivity of the XLZD Rare Event Observatory

Authors: XLZD Collaboration, J. Aalbers, K. Abe, M. Adrover, S. Ahmed Maouloud, D. S. Akerib, A. K. Al Musalhi, F. Alder, L. Althueser, D. W. P. Amaral, C. S. Amarasinghe, A. Ames, B. Andrieu, N. Angelides, E. Angelino, B. Antunovic, E. Aprile, H. M. Araújo, J. E. Armstrong, M. Arthurs, M. Babicz, D. Bajpai, A. Baker, M. Balzer, J. Bang , et al. (419 additional authors not shown)

Abstract: The XLZD collaboration is developing a two-phase xenon time projection chamber with an active mass of 60 to 80 t capable of probing the remaining WIMP-nucleon interaction parameter space down to the so-called neutrino fog. In this work we show that, based on the performance of currently operating detectors using the same technology and a realistic reduction of radioactivity in detector materials,… ▽ More The XLZD collaboration is developing a two-phase xenon time projection chamber with an active mass of 60 to 80 t capable of probing the remaining WIMP-nucleon interaction parameter space down to the so-called neutrino fog. In this work we show that, based on the performance of currently operating detectors using the same technology and a realistic reduction of radioactivity in detector materials, such an experiment will also be able to competitively search for neutrinoless double beta decay in $^{136}$Xe using a natural-abundance xenon target. XLZD can reach a 3$σ$ discovery potential half-life of 5.7$\times$10$^{27}$ yr (and a 90% CL exclusion of 1.3$\times$10$^{28}$ yr) with 10 years of data taking, corresponding to a Majorana mass range of 7.3-31.3 meV (4.8-20.5 meV). XLZD will thus exclude the inverted neutrino mass ordering parameter space and will start to probe the normal ordering region for most of the nuclear matrix elements commonly considered by the community. △ Less

Submitted 30 April, 2025; v1 submitted 23 October, 2024; originally announced October 2024.

Comments: 29 pages, 7 figures

Journal ref: J. Phys. G: Nucl. Part. Phys. 52 (2025) 045102

First Indication of Solar $^8$B Neutrinos via Coherent Elastic Neutrino-Nucleus Scattering with XENONnT

Authors: E. Aprile, J. Aalbers, K. Abe, S. Ahmed Maouloud, L. Althueser, B. Andrieu, E. Angelino, D. Antón Martin, F. Arneodo, L. Baudis, M. Bazyk, L. Bellagamba, R. Biondi, A. Bismark, K. Boese, A. Brown, G. Bruno, R. Budnik, C. Cai, C. Capelli, J. M. R. Cardoso, A. P. Cimental Chávez, A. P. Colijn, J. Conrad, J. J. Cuenca-García , et al. (142 additional authors not shown)

Abstract: We present the first measurement of nuclear recoils from solar $^8$B neutrinos via coherent elastic neutrino-nucleus scattering with the XENONnT dark matter experiment. The central detector of XENONnT is a low-background, two-phase time projection chamber with a 5.9 t sensitive liquid xenon target. A blind analysis with an exposure of 3.51 t$\times$yr resulted in 37 observed events above 0.5 keV,… ▽ More We present the first measurement of nuclear recoils from solar $^8$B neutrinos via coherent elastic neutrino-nucleus scattering with the XENONnT dark matter experiment. The central detector of XENONnT is a low-background, two-phase time projection chamber with a 5.9 t sensitive liquid xenon target. A blind analysis with an exposure of 3.51 t$\times$yr resulted in 37 observed events above 0.5 keV, with ($26.4^{+1.4}_{-1.3}$) events expected from backgrounds. The background-only hypothesis is rejected with a statistical significance of 2.73 $σ$. The measured $^8$B solar neutrino flux of $(4.7_{-2.3}^{+3.6})\times 10^6 \mathrm{cm}^{-2}\mathrm{s}^{-1}$ is consistent with results from the Sudbury Neutrino Observatory. The measured neutrino flux-weighted CE$ν$NS cross section on Xe of $(1.1^{+0.8}_{-0.5})\times10^{-39} \mathrm{cm}^2$ is consistent with the Standard Model prediction. This is the first direct measurement of nuclear recoils from solar neutrinos with a dark matter detector. △ Less

Submitted 23 November, 2024; v1 submitted 5 August, 2024; originally announced August 2024.

Journal ref: Phys. Rev. Lett. 133, 191002 (2024)

Supernova Pointing Capabilities of DUNE

Authors: DUNE Collaboration, A. Abed Abud, B. Abi, R. Acciarri, M. A. Acero, M. R. Adames, G. Adamov, M. Adamowski, D. Adams, M. Adinolfi, C. Adriano, A. Aduszkiewicz, J. Aguilar, B. Aimard, F. Akbar, K. Allison, S. Alonso Monsalve, M. Alrashed, A. Alton, R. Alvarez, T. Alves, H. Amar, P. Amedo, J. Anderson, D. A. Andrade , et al. (1340 additional authors not shown)

Abstract: The determination of the direction of a stellar core collapse via its neutrino emission is crucial for the identification of the progenitor for a multimessenger follow-up. A highly effective method of reconstructing supernova directions within the Deep Underground Neutrino Experiment (DUNE) is introduced. The supernova neutrino pointing resolution is studied by simulating and reconstructing electr… ▽ More The determination of the direction of a stellar core collapse via its neutrino emission is crucial for the identification of the progenitor for a multimessenger follow-up. A highly effective method of reconstructing supernova directions within the Deep Underground Neutrino Experiment (DUNE) is introduced. The supernova neutrino pointing resolution is studied by simulating and reconstructing electron-neutrino charged-current absorption on 40Ar and elastic scattering of neutrinos on electrons. Procedures to reconstruct individual interactions, including a newly developed technique called ``brems flipping'', as well as the burst direction from an ensemble of interactions are described. Performance of the burst direction reconstruction is evaluated for supernovae happening at a distance of 10 kpc for a specific supernova burst flux model. The pointing resolution is found to be 3.4 degrees at 68% coverage for a perfect interaction-channel classification and a fiducial mass of 40 kton, and 6.6 degrees for a 10 kton fiducial mass respectively. Assuming a 4% rate of charged-current interactions being misidentified as elastic scattering, DUNE's burst pointing resolution is found to be 4.3 degrees (8.7 degrees) at 68% coverage. △ Less

Submitted 24 December, 2025; v1 submitted 14 July, 2024; originally announced July 2024.

Comments: 26 pages, 17 figures

Report number: FERMILAB-PUB-24-0319-LBNF

Journal ref: Phys. Rev. D 111, 092006 (Published 12 May, 2025)

Measurement of nuclear effects in neutrino-argon interactions using generalized kinematic imbalance variables with the MicroBooNE detector

Authors: MicroBooNE collaboration, P. Abratenko, O. Alterkait, D. Andrade Aldana, L. Arellano, J. Asaadi, A. Ashkenazi, S. Balasubramanian, B. Baller, G. Barr, D. Barrow, J. Barrow, V. Basque, O. Benevides Rodrigues, S. Berkman, A. Bhanderi, A. Bhat, M. Bhattacharya, M. Bishai, A. Blake, B. Bogart, T. Bolton, J. Y. Book, M. B. Brunetti, L. Camilleri , et al. (163 additional authors not shown)

Abstract: We present a set of new generalized kinematic imbalance variables that can be measured in neutrino scattering. These variables extend previous measurements of kinematic imbalance on the transverse plane, and are more sensitive to modeling of nuclear effects. We demonstrate the enhanced power of these variables using simulation, and then use the MicroBooNE detector to measure them for the first tim… ▽ More We present a set of new generalized kinematic imbalance variables that can be measured in neutrino scattering. These variables extend previous measurements of kinematic imbalance on the transverse plane, and are more sensitive to modeling of nuclear effects. We demonstrate the enhanced power of these variables using simulation, and then use the MicroBooNE detector to measure them for the first time. We report flux-integrated single- and double-differential measurements of charged-current muon neutrino scattering on argon using a topolgy with one muon and one proton in the final state as a function of these novel kinematic imbalance variables. These measurements allow us to demonstrate that the treatment of charged current quasielastic interactions in GENIE version 2 is inadequate to describe data. Further, they reveal tensions with more modern generator predictions particularly in regions of phase space where final state interactions are important. △ Less

Submitted 16 May, 2024; v1 submitted 9 October, 2023; originally announced October 2023.

Journal ref: Phys. Rev. D 109, 092007 (2024)

First Measurement of Differential Cross Sections for Muon Neutrino Charged Current Interactions on Argon with a Two-proton Final State in the MicroBooNE Detector

Authors: MicroBooNE collaboration, P. Abratenko, D. Andrade Aldana, L. Arellano, J. Asaadi, A. Ashkenazi, S. Balasubramanian, B. Baller, A. Barnard, G. Barr, D. Barrow, J. Barrow, V. Basque, J. Bateman, L. Bathe-Peters, O. Benevides Rodrigues, S. Berkman, A. Bhanderi, A. Bhat, M. Bhattacharya, M. Bishai, A. Blake, B. Bogart, T. Bolton, J. Y. Book , et al. (177 additional authors not shown)

Abstract: We present the first measurement of differential cross sections for charged-current muon neutrino interactions on argon with one muon, two protons, and no pions in the final state. These final states are dominated by two-nucleon knockout interactions, which are complicated to model and for which there is currently limited information about the characteristics of these interactions in existing neut… ▽ More We present the first measurement of differential cross sections for charged-current muon neutrino interactions on argon with one muon, two protons, and no pions in the final state. These final states are dominated by two-nucleon knockout interactions, which are complicated to model and for which there is currently limited information about the characteristics of these interactions in existing neutrino-nucleus scattering data. Detailed investigations of two-nucleon knockout are vital to support upcoming experiments exploring the nature of the neutrino. Among the different kinematic quantities measured, the opening angle between the two protons, the angle between the total proton momentum and the muon, and the total transverse momentum of the final state system are most sensitive to the underlying physics processes as embodied in various theoretical models. △ Less

Submitted 25 February, 2025; v1 submitted 7 November, 2022; originally announced November 2022.

Comments: Resubmitted to address previous referee comments (previously submitted to PRL). 5 Figures

Report number: FERMILAB-PUB-22-836-ND

Journal ref: 10.1016/j.physletb.2025.140052

Double-Weak Decays of $^{124}$Xe and $^{136}$Xe in the XENON1T and XENONnT Experiments

Authors: E. Aprile, K. Abe, F. Agostini, S. Ahmed Maouloud, M. Alfonsi, L. Althueser, B. Andrieu, E. Angelino, J. R. Angevaare, V. C. Antochi, D. Antón Martin, F. Arneodo, L. Baudis, A. L. Baxter, L. Bellagamba, R. Biondi, A. Bismark, A. Brown, S. Bruenner, G. Bruno, R. Budnik, C. Cai, C. Capelli, J. M. R. Cardoso, D. Cichon , et al. (135 additional authors not shown)

Abstract: We present results on the search for double-electron capture ($2ν\text{ECEC}$) of $^{124}$Xe and neutrinoless double-$β$ decay ($0νββ$) of $^{136}$Xe in XENON1T. We consider captures from the K- up to the N-shell in the $2ν\text{ECEC}$ signal model and measure a total half-life of $T_{1/2}^{2ν\text{ECEC}}=(1.1\pm0.2_\text{stat}\pm0.1_\text{sys})\times 10^{22}\;\text{yr}$ with a… ▽ More We present results on the search for double-electron capture ($2ν\text{ECEC}$) of $^{124}$Xe and neutrinoless double-$β$ decay ($0νββ$) of $^{136}$Xe in XENON1T. We consider captures from the K- up to the N-shell in the $2ν\text{ECEC}$ signal model and measure a total half-life of $T_{1/2}^{2ν\text{ECEC}}=(1.1\pm0.2_\text{stat}\pm0.1_\text{sys})\times 10^{22}\;\text{yr}$ with a $0.87\;\text{kg}\times\text{yr}$ isotope exposure. The statistical significance of the signal is $7.0\,σ$. We use XENON1T data with $36.16\;\text{kg}\times\text{yr}$ of $^{136}$Xe exposure to search for $0νββ$. We find no evidence of a signal and set a lower limit on the half-life of $T_{1/2}^{0νββ} > 1.2 \times 10^{24}\;\text{yr}\; \text{at}\; 90\,\%\;\text{CL}$. This is the best result from a dark matter detector without an enriched target to date. We also report projections on the sensitivity of XENONnT to $0νββ$. Assuming a $275\;\text{kg}\times\text{yr}$ $^{136}$Xe exposure, the expected sensitivity is $T_{1/2}^{0νββ} > 2.1 \times 10^{25}\;\text{yr}\; \text{at}\; 90\,\%\;\text{CL}$, corresponding to an effective Majorana mass range of $\langle m_{ββ} \rangle < (0.19 - 0.59)\;\text{eV/c}^2$. △ Less

Submitted 6 September, 2022; v1 submitted 9 May, 2022; originally announced May 2022.

Comments: 23 pages, 14 figures, 9 tables, version accepted for publication in Phys. Rev. C

Journal ref: Phys. Rev. C 106, 024328 (2022)

A Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics

Authors: J. Aalbers, K. Abe, V. Aerne, F. Agostini, S. Ahmed Maouloud, D. S. Akerib, D. Yu. Akimov, J. Akshat, A. K. Al Musalhi, F. Alder, S. K. Alsum, L. Althueser, C. S. Amarasinghe, F. D. Amaro, A. Ames, T. J. Anderson, B. Andrieu, N. Angelides, E. Angelino, J. Angevaare, V. C. Antochi, D. Antón Martin, B. Antunovic, E. Aprile, H. M. Araújo , et al. (572 additional authors not shown)

Abstract: The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neut… ▽ More The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector. △ Less

Submitted 4 March, 2022; originally announced March 2022.

Comments: 77 pages, 40 figures, 1262 references

Report number: INT-PUB-22-003

Journal ref: J. Phys. G: Nucl. Part. Phys. 50 (2023) 013001

MiniBooNE and MicroBooNE Combined Fit to a 3+1 Sterile Neutrino Scenario

Authors: A. A. Aguilar-Arevalo, B. C. Brown, J. M. Conrad, R. Dharmapalan, A. Diaz, Z. Djurcic, D. A. Finley, R. Ford, G. T. Garvey, S. Gollapinni, A. Hourlier, E. -C. Huang, N. W. Kamp, G. Karagiorgi, T. Katori, T. Kobilarcik, K. Lin, W. C. Louis, C. Mariani, W. Marsh, G. B. Mills, J. Mirabal-Martinez, C. D. Moore, R. H. Nelson, J. Nowak , et al. (14 additional authors not shown)

Abstract: This letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short-baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experim… ▽ More This letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short-baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experiment. We present the 3+1 fit to the MiniBooNE electron-(anti)neutrino and muon-(anti)neutrino data alone, and in combination with MicroBooNE electron-neutrino data. The best-fit parameters of the combined fit with the exclusive CCQE analysis (inclusive analysis) are $Δm^2 = 0.29 eV^2 (0.33 eV^2)$, $|U_{e4}|^2 = 0.016 (0.500)$, $|U_{μ4}|^2 = 0.500 (0.500)$, and $\sin^2(2θ_{μe})=0.0316 (1.0)$. Comparing the no-oscillation scenario to the 3+1 model, the data prefer the 3+1 model with a $Δχ^2/\text{dof} = 24.7 / 3 (17.3 / 3)$, a $4.3σ(3.4σ)$ preference assuming the asymptotic approximation given by Wilks' theorem. △ Less

Submitted 9 September, 2022; v1 submitted 5 January, 2022; originally announced January 2022.

Comments: 10 pages, 4 figures, 2 table

MiniBooNE Data Releases

Authors: A. A. Aguilar-Arevalo, B. C. Brown, J. M. Conrad, R. Dharmapalan, A. Diaz, Z. Djurcic, D. A. Finley, R. Ford, G. T. Garvey, S. Gollapinni, A. Hourlier, E. -C. Huang, N. W. Kamp, G. Karagiorgi, T. Katori, T. Kobilarcik, K. Lin, W. C. Louis, C. Mariani, W. Marsh, G. B. Mills, J. Mirabal-Martinez, C. D. Moore, R. H. Nelson, J. Nowak , et al. (16 additional authors not shown)

Abstract: The MiniBooNE experiment has provided data releases for most publications. Occasionally it is necessary to move data release pages. This document provides a single point of reference that will be updated by the collaboration to point to the present location of the MiniBooNE data releases. The MiniBooNE experiment has provided data releases for most publications. Occasionally it is necessary to move data release pages. This document provides a single point of reference that will be updated by the collaboration to point to the present location of the MiniBooNE data releases. △ Less

Submitted 25 October, 2021; originally announced October 2021.

Comments: 2 pages, 0 figures

Measurement of Differential Cross Sections for $ν_μ$-Ar Charged-Current Interactions with Protons and no Pions in the Final State with the MicroBooNE Detector

Authors: MicroBooNE collaboration, P. Abratenko, M. Alrashed, R. An, J. Anthony, J. Asaadi, A. Ashkenazi, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, V. Basque, L. Bathe-Peters, O. Benevides Rodrigues, S. Berkman, A. Bhanderi, A. Bhat, M. Bishai, A. Blake, T. Bolton, L. Camilleri, D. Caratelli, I. Caro Terrazas, R. Castillo Fernandez, F. Cavanna , et al. (160 additional authors not shown)

Abstract: We present an analysis of MicroBooNE data with a signature of one muon, no pions, and at least one proton above a momentum threshold of 300 MeV/c (CC0$π$Np). This is the first differential cross section measurement of this topology in neutrino-argon interactions. We achieve a significantly lower proton momentum threshold than previous carbon and scintillator-based experiments. Using data collected… ▽ More We present an analysis of MicroBooNE data with a signature of one muon, no pions, and at least one proton above a momentum threshold of 300 MeV/c (CC0$π$Np). This is the first differential cross section measurement of this topology in neutrino-argon interactions. We achieve a significantly lower proton momentum threshold than previous carbon and scintillator-based experiments. Using data collected from a total of approximately $1.6 \times 10^{20}$ protons-on-target, we measure the muon neutrino cross section for the CC0$π$Np interaction channel in argon at MicroBooNE in the Booster Neutrino Beam which has a mean energy of around 800 MeV. We present the results from a data sample with estimated efficiency of 29\% and purity of 76\% as differential cross sections in five reconstructed variables: the muon momentum and polar angle, the leading proton momentum and polar angle, and the muon-proton opening angle. We include smearing matrices that can be used to "forward-fold" theoretical predictions for comparison with these data. We compare the measured differential cross sections to a number of recent theory predictions demonstrating largely good agreement with this first-ever data set on argon. △ Less

Submitted 5 October, 2020; originally announced October 2020.

Comments: 24 pages, 43 figures, 1 table and supplemental material

Report number: FERMILAB-PUB-20-505-AD-ND-SCD-TD

Journal ref: Phys. Rev. D 102, 112013 (2020)

Supernova Neutrino Burst Detection with the Deep Underground Neutrino Experiment

Authors: DUNE collaboration, B. Abi, R. Acciarri, M. A. Acero, G. Adamov, D. Adams, M. Adinolfi, Z. Ahmad, J. Ahmed, T. Alion, S. Alonso Monsalve, C. Alt, J. Anderson, C. Andreopoulos, M. P. Andrews, F. Andrianala, S. Andringa, A. Ankowski, M. Antonova, S. Antusch, A. Aranda-Fernandez, A. Ariga, L. O. Arnold, M. A. Arroyave, J. Asaadi , et al. (949 additional authors not shown)

Abstract: The Deep Underground Neutrino Experiment (DUNE), a 40-kton underground liquid argon time projection chamber experiment, will be sensitive to the electron-neutrino flavor component of the burst of neutrinos expected from the next Galactic core-collapse supernova. Such an observation will bring unique insight into the astrophysics of core collapse as well as into the properties of neutrinos. The gen… ▽ More The Deep Underground Neutrino Experiment (DUNE), a 40-kton underground liquid argon time projection chamber experiment, will be sensitive to the electron-neutrino flavor component of the burst of neutrinos expected from the next Galactic core-collapse supernova. Such an observation will bring unique insight into the astrophysics of core collapse as well as into the properties of neutrinos. The general capabilities of DUNE for neutrino detection in the relevant few- to few-tens-of-MeV neutrino energy range will be described. As an example, DUNE's ability to constrain the $ν_e$ spectral parameters of the neutrino burst will be considered. △ Less

Submitted 29 May, 2021; v1 submitted 15 August, 2020; originally announced August 2020.

Comments: 29 pages, 17 figures; paper based on DUNE Technical Design Report. arXiv admin note: substantial text overlap with arXiv:2002.03005

Report number: FERMILAB-PUB-20-380-LBNF

Updated MiniBooNE Neutrino Oscillation Results with Increased Data and New Background Studies

Authors: MiniBooNE Collaboration, A. A. Aguilar-Arevalo, B. C. Brown, J. M. Conrad, R. Dharmapalan, A. Diaz, Z. Djurcic, D. A. Finley, R. Ford, G. T. Garvey, S. Gollapinni, A. Hourlier, E. C. Huang, N. W. Kamp, G. Karagiorgi, T. Katori, T. Kobilarcik, K. Lin, W. C. Louis, C. Mariani, W. Marsh, G. B. Mills, J. Mirabal-Martinez, C. D. Moore, R. H. Nelson , et al. (17 additional authors not shown)

Abstract: The MiniBooNE experiment at Fermilab reports a total excess of $638.0 \pm 132.8$ electron-like events ($4.8 σ$) from a data sample corresponding to $18.75 \times 10^{20}$ protons-on-target in neutrino mode, which is a 46\% increase in the data sample with respect to previously published results, and $11.27 \times 10^{20}$ protons-on-target in antineutrino mode. The additional statistics allow seve… ▽ More The MiniBooNE experiment at Fermilab reports a total excess of $638.0 \pm 132.8$ electron-like events ($4.8 σ$) from a data sample corresponding to $18.75 \times 10^{20}$ protons-on-target in neutrino mode, which is a 46\% increase in the data sample with respect to previously published results, and $11.27 \times 10^{20}$ protons-on-target in antineutrino mode. The additional statistics allow several studies to address questions on the source of the excess. First, we provide two-dimensional plots in visible energy and cosine of the angle of the outgoing lepton, which can provide valuable input to models for the event excess. Second, we test whether the excess may arise from photons that enter the detector from external events or photons exiting the detector from $π^0$ decays in two model independent ways. Beam timing information shows that almost all of the excess is in time with neutrinos that interact in the detector. The radius distribution shows that the excess is distributed throughout the volume, while tighter cuts on the fiducal volume increase the significance of the excess. We conclude that models of the event excess based on entering and exiting photons are disfavored. △ Less

Submitted 8 March, 2021; v1 submitted 30 June, 2020; originally announced June 2020.

Comments: 28 pages, 26 figures

Report number: LA-UR-20-29235

Journal ref: Phys. Rev. D 103, 052002 (2021)

First Measurement of Differential Charged Current Quasielastic-like $ν_μ$-Argon Scattering Cross Sections with the MicroBooNE Detector

Authors: P. Abratenko, M. Alrashed, R. An, J. Anthony, J. Asaadi, A. Ashkenazi, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, V. Basque, L. Bathe-Peters, O. Benevides Rodrigues, S. Berkman, A. Bhanderi, A. Bhat, M. Bishai, A. Blake, T. Bolton, L. Camilleri, D. Caratelli, I. Caro Terrazas, R. Castillo Fernandez, F. Cavanna, G. Cerati , et al. (159 additional authors not shown)

Abstract: We report on the first measurement of flux-integrated single differential cross sections for charged-current (CC) muon neutrino ($ν_μ$) scattering on argon with a muon and a proton in the final state, $^{40}$Ar($ν_μ$,$μ$p)X. The measurement was carried out using the Booster Neutrino Beam at Fermi National Accelerator Laboratory and the MicroBooNE liquid argon time projection chamber detector with… ▽ More We report on the first measurement of flux-integrated single differential cross sections for charged-current (CC) muon neutrino ($ν_μ$) scattering on argon with a muon and a proton in the final state, $^{40}$Ar($ν_μ$,$μ$p)X. The measurement was carried out using the Booster Neutrino Beam at Fermi National Accelerator Laboratory and the MicroBooNE liquid argon time projection chamber detector with an exposure of 4.59 $\times$ 10$^{19}$ protons on target. Events are selected to enhance the contribution of CC quasielastic (CCQE) interactions. The data are reported in terms of a total cross section as well as single differential cross sections in final state muon and proton kinematics. We measure the integrated per-nucleus CCQE-like cross section (i.e. for interactions leading to a muon, one proton and no pions above detection threshold) of (4.93 $\pm$ 0.76stat $\pm$ 1.29sys) $\times$ 10$^{-38}$cm$^2$, in good agreement with theoretical calculations. The single differential cross sections are also in overall good agreement with theoretical predictions, except at very forward muon scattering angles that correspond to low momentum-transfer events. △ Less

Submitted 5 October, 2020; v1 submitted 29 May, 2020; originally announced June 2020.

Comments: Accepted for publication in PRL. 8 pages, 3 figures, 1 table and online supplementary materials

Report number: FNAL PUB-20-226-ND

Journal ref: Phys. Rev. Lett. 125, 201803 (2020)

Energy resolution and linearity of XENON1T in the MeV energy range

Authors: E. Aprile, J. Aalbers, F. Agostini, M. Alfonsi, L. Althueser, F. D. Amaro, V. C. Antochi, E. Angelino, J. Angevaare, F. Arneodo, D. Barge, L. Baudis, B. Bauermeister, L. Bellagamba, M. L. Benabderrahmane, T. Berger, P. A. Breur, A. Brown, E. Brown, S. Bruenner, G. Bruno, R. Budnik, C. Capelli, J. M. R. Cardoso, D. Cichon , et al. (113 additional authors not shown)

Abstract: Xenon dual-phase time projection chambers designed to search for Weakly Interacting Massive Particles have so far shown a relative energy resolution which degrades with energy above $\sim$200 keV due to the saturation effects. This has limited their sensitivity in the search for rare events like the neutrinoless double-beta decay of $^{136}$Xe at its $Q$-value, $Q_{ββ}\simeq$ 2.46 MeV. For the XEN… ▽ More Xenon dual-phase time projection chambers designed to search for Weakly Interacting Massive Particles have so far shown a relative energy resolution which degrades with energy above $\sim$200 keV due to the saturation effects. This has limited their sensitivity in the search for rare events like the neutrinoless double-beta decay of $^{136}$Xe at its $Q$-value, $Q_{ββ}\simeq$ 2.46 MeV. For the XENON1T dual-phase time projection chamber, we demonstrate that the relative energy resolution at 1 $σ/μ$ is as low as (0.80$\pm$0.02) % in its one-ton fiducial mass, and for single-site interactions at $Q_{ββ}$. We also present a new signal correction method to rectify the saturation effects of the signal readout system, resulting in more accurate position reconstruction and indirectly improving the energy resolution. The very good result achieved in XENON1T opens up new windows for the xenon dual-phase dark matter detectors to simultaneously search for other rare events. △ Less

Submitted 9 September, 2020; v1 submitted 8 March, 2020; originally announced March 2020.

Comments: 9 pages, 7 figures

Journal ref: Eur. Phys. J. C 80, 785 (2020)

First observation of two-neutrino double electron capture in $^{124}$Xe with XENON1T

Authors: E. Aprile, J. Aalbers, F. Agostini, M. Alfonsi, L. Althueser, F. D. Amaro, M. Anthony, V. C. Antochi, F. Arneodo, L. Baudis, B. Bauermeister, M. L. Benabderrahmane, T. Berger, P. A. Breur, A. Brown, A. Brown, E. Brown, S. Bruenner, G. Bruno, R. Budnik, C. Capelli, J. M. R. Cardoso, D. Cichon, D. Coderre, A. P. Colijn , et al. (106 additional authors not shown)

Abstract: Two-neutrino double electron capture ($2ν$ECEC) is a second-order Weak process with predicted half-lives that surpass the age of the Universe by many orders of magnitude. Until now, indications for $2ν$ECEC decays have only been seen for two isotopes, $^{78}$Kr and $^{130}$Ba, and instruments with very low background levels are needed to detect them directly with high statistical significance. The… ▽ More Two-neutrino double electron capture ($2ν$ECEC) is a second-order Weak process with predicted half-lives that surpass the age of the Universe by many orders of magnitude. Until now, indications for $2ν$ECEC decays have only been seen for two isotopes, $^{78}$Kr and $^{130}$Ba, and instruments with very low background levels are needed to detect them directly with high statistical significance. The $2ν$ECEC half-life provides an important input for nuclear structure models and its measurement represents a first step in the search for the neutrinoless double electron capture processes ($0ν$ECEC). A detection of the latter would have implications for the nature of the neutrino and give access to the absolute neutrino mass. Here we report on the first direct observation of $2ν$ECEC in $^{124}$Xe with the XENON1T Dark Matter detector. The significance of the signal is $4.4σ$ and the corresponding half-life $T_{1/2}^{2ν\text{ECEC}} = (1.8\pm 0.5_\text{stat}\pm 0.1_\text{sys})\times 10^{22}\;\text{y}$ is the longest ever measured directly. This study demonstrates that the low background and large target mass of xenon-based Dark Matter detectors make them well suited to measuring other rare processes as well, and it highlights the broad physics reach for even larger next-generation experiments. △ Less

Submitted 24 April, 2019; originally announced April 2019.

Journal ref: Nature 568, p.532-535, 2019

Rejecting cosmic background for exclusive neutrino interaction studies with Liquid Argon TPCs; a case study with the MicroBooNE detector

Authors: MicroBooNE collaboration, C. Adams, M. Alrashed, R. An, J. Anthony, J. Asaadi, A. Ashkenazi, M. Auger, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, M. Bass, F. Bay, A. Bhat, K. Bhattacharya, M. Bishai, A. Blake, T. Bolton, L. Camilleri, D. Caratelli, I. Caro Terrazas, R. Carr, R. Castillo Fernandez, F. Cavanna , et al. (150 additional authors not shown)

Abstract: Cosmic ray (CR) interactions can be a challenging source of background for neutrino oscillation and cross-section measurements in surface detectors. We present methods for CR rejection in measurements of charged-current quasielastic-like (CCQE-like) neutrino interactions, with a muon and a proton in the final state, measured using liquid argon time projection chambers (LArTPCs). Using a sample of… ▽ More Cosmic ray (CR) interactions can be a challenging source of background for neutrino oscillation and cross-section measurements in surface detectors. We present methods for CR rejection in measurements of charged-current quasielastic-like (CCQE-like) neutrino interactions, with a muon and a proton in the final state, measured using liquid argon time projection chambers (LArTPCs). Using a sample of cosmic data collected with the MicroBooNE detector, mixed with simulated neutrino scattering events, a set of event selection criteria is developed that produces an event sample with minimal contribution from CR background. Depending on the selection criteria used a purity between 50% and 80% can be achieved with a signal selection efficiency between 50% and 25%, with higher purity coming at the expense of lower efficiency. While using a specific dataset from the MicroBooNE detector and selection criteria values optimized for CCQE-like events, the concepts presented here are generic and can be adapted for various studies of exclusive νμ interactions in LArTPCs. △ Less

Submitted 2 January, 2019; v1 submitted 9 December, 2018; originally announced December 2018.

Comments: 12 pages, 10 figures, 1 table

Report number: FERMILAB-PUB-18-677-E

Measurements using the inelasticity distribution of multi-TeV neutrino interactions in IceCube

Authors: IceCube Collaboration, M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, I. Al Samarai, D. Altmann, K. Andeen, T. Anderson, I. Ansseau, G. Anton, C. Argüelles, J. Auffenberg, S. Axani, P. Backes, H. Bagherpour, X. Bai, A. Barbano, J. P. Barron, S. W. Barwick, V. Baum, R. Bay, J. J. Beatty , et al. (309 additional authors not shown)

Abstract: Inelasticity--the fraction of a neutrino's energy transferred to hadrons--is a quantity of interest in the study of astrophysical and atmospheric neutrino interactions at multi-TeV energies with IceCube. In this work, a sample of contained neutrino interactions in IceCube is obtained from 5 years of data and classified as 2650 tracks and 965 cascades. Tracks arise predominantly from charged-curren… ▽ More Inelasticity--the fraction of a neutrino's energy transferred to hadrons--is a quantity of interest in the study of astrophysical and atmospheric neutrino interactions at multi-TeV energies with IceCube. In this work, a sample of contained neutrino interactions in IceCube is obtained from 5 years of data and classified as 2650 tracks and 965 cascades. Tracks arise predominantly from charged-current $ν_μ$ interactions, and we demonstrate that we can reconstruct their energy and inelasticity. The inelasticity distribution is found to be consistent with the calculation of Cooper-Sarkar et al. across the energy range from $\sim$ 1 TeV to $\sim$ 100 TeV. Along with cascades from neutrinos of all flavors, we also perform a fit over the energy, zenith angle, and inelasticity distribution to characterize the flux of astrophysical and atmospheric neutrinos. The energy spectrum of diffuse astrophysical neutrinos is well-described by a power-law in both track and cascade samples, and a best-fit index $γ=2.62\pm0.07$ is found in the energy range from 3.5 TeV to 2.6 PeV. Limits are set on the astrophysical flavor composition that are compatible with a ratio of $\left(\frac{1}{3}:\frac{1}{3}:\frac{1}{3}\right)_{\oplus}$. Exploiting the distinct inelasticity distribution of $ν_μ$ and $\barν_μ$ interactions, the atmospheric $ν_μ$ to $\barν_μ$ flux ratio in the energy range from 770 GeV to 21 TeV is found to be $0.77^{+0.44}_{-0.25}$ times the calculation by Honda et al. Lastly, the inelasticity distribution is also sensitive to neutrino charged-current charm production. The data are consistent with a leading-order calculation, with zero charm production excluded at $91\%$ confidence level. Future analyses of inelasticity distributions may probe new physics that affects neutrino interactions both in and beyond the Standard Model. △ Less

Submitted 24 February, 2019; v1 submitted 23 August, 2018; originally announced August 2018.

Comments: 20 pages, 13 figures

Journal ref: Phys. Rev. D 99, 032004 (2019)

Ionization Electron Signal Processing in Single Phase LArTPCs II. Data/Simulation Comparison and Performance in MicroBooNE

Authors: MicroBooNE collaboration, C. Adams, R. An, J. Anthony, J. Asaadi, M. Auger, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, M. Bass, F. Bay, A. Bhat, K. Bhattacharya, M. Bishai, A. Blake, T. Bolton, L. Camilleri, D. Caratelli, R. Carr, I. Caro Terrazas, R. Castillo Fernandez, F. Cavanna, G. Cerati, H. Chen , et al. (146 additional authors not shown)

Abstract: The single-phase liquid argon time projection chamber (LArTPC) provides a large amount of detailed information in the form of fine-grained drifted ionization charge from particle traces. To fully utilize this information, the deposited charge must be accurately extracted from the raw digitized waveforms via a robust signal processing chain. Enabled by the ultra-low noise levels associated with cry… ▽ More The single-phase liquid argon time projection chamber (LArTPC) provides a large amount of detailed information in the form of fine-grained drifted ionization charge from particle traces. To fully utilize this information, the deposited charge must be accurately extracted from the raw digitized waveforms via a robust signal processing chain. Enabled by the ultra-low noise levels associated with cryogenic electronics in the MicroBooNE detector, the precise extraction of ionization charge from the induction wire planes in a single-phase LArTPC is qualitatively demonstrated on MicroBooNE data with event display images, and quantitatively demonstrated via waveform-level and track-level metrics. Improved performance of induction plane calorimetry is demonstrated through the agreement of extracted ionization charge measurements across different wire planes for various event topologies. In addition to the comprehensive waveform-level comparison of data and simulation, a calibration of the cryogenic electronics response is presented and solutions to various MicroBooNE-specific TPC issues are discussed. This work presents an important improvement in LArTPC signal processing, the foundation of reconstruction and therefore physics analyses in MicroBooNE. △ Less

Submitted 11 June, 2018; v1 submitted 7 April, 2018; originally announced April 2018.

Comments: 54 pages, 36 figures; the first part of this work can be found at arXiv:1802.08709

Journal ref: JINST 13 P07007 (2018)

Ionization Electron Signal Processing in Single Phase LArTPCs I. Algorithm Description and Quantitative Evaluation with MicroBooNE Simulation

Authors: MicroBooNE collaboration, C. Adams, R. An, J. Anthony, J. Asaadi, M. Auger, L. Bagby, S. Balasubramanian, B. Baller, C. Barnes, G. Barr, M. Bass, F. Bay, A. Bhat, K. Bhattacharya, M. Bishai, A. Blake, T. Bolton, L. Camilleri, D. Caratelli, R. Castillo Fernandez, F. Cavanna, G. Cerati, H. Chen, Y. Chen , et al. (144 additional authors not shown)

Abstract: We describe the concept and procedure of drifted-charge extraction developed in the MicroBooNE experiment, a single-phase liquid argon time projection chamber (LArTPC). This technique converts the raw digitized TPC waveform to the number of ionization electrons passing through a wire plane at a given time. A robust recovery of the number of ionization electrons from both induction and collection a… ▽ More We describe the concept and procedure of drifted-charge extraction developed in the MicroBooNE experiment, a single-phase liquid argon time projection chamber (LArTPC). This technique converts the raw digitized TPC waveform to the number of ionization electrons passing through a wire plane at a given time. A robust recovery of the number of ionization electrons from both induction and collection anode wire planes will augment the 3D reconstruction, and is particularly important for tomographic reconstruction algorithms. A number of building blocks of the overall procedure are described. The performance of the signal processing is quantitatively evaluated by comparing extracted charge with the true charge through a detailed TPC detector simulation taking into account position-dependent induced current inside a single wire region and across multiple wires. Some areas for further improvement of the performance of the charge extraction procedure are also discussed. △ Less

Submitted 9 April, 2018; v1 submitted 23 February, 2018; originally announced February 2018.

Comments: 60 pages, 36 figures. The second part of this work can be found at arXiv:1804.02583

Journal ref: JINST 13 P07006 (2018)

First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions

Authors: A. A. Aguilar-Arevalo, B. C. Brown, L. Bugel, G. Cheng, E. D. Church, J. M. Conrad, R. L. Cooper, R. Dharmapalan, Z. Djurcic, D. A. Finley, R. S. Fitzpatrick, R. Ford, F. G. Garcia, G. T. Garvey, J. Grange, W. Huelsnitz, C. Ignarra, R. Imlay, R. A. Johnson, J. R. Jordan, G. Karagiorgi, T. Katori, T. Kobilarcik, W. C. Louis, K. Mahn , et al. (24 additional authors not shown)

Abstract: We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest ($K^+ \rightarrow μ^+ ν_μ$) at the NuMI beamline absorber. These signal $ν_μ$-carbon events are distinguished from primarily pion decay in flight $ν_μ$ and $\overlineν_μ$ backgrounds produced at the target stati… ▽ More We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest ($K^+ \rightarrow μ^+ ν_μ$) at the NuMI beamline absorber. These signal $ν_μ$-carbon events are distinguished from primarily pion decay in flight $ν_μ$ and $\overlineν_μ$ backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9$σ$ level. The muon kinetic energy, neutrino-nucleus energy transfer ($ω=E_ν-E_μ$), and total cross section for these events is extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of $ω$ using neutrinos, a quantity thus far only accessible through electron scattering. △ Less

Submitted 7 May, 2018; v1 submitted 11 January, 2018; originally announced January 2018.

Comments: 6 pages, 4 figures

Journal ref: Phys. Rev. Lett. 120, 141802 (2018)

Measurement of the multi-TeV neutrino cross section with IceCube using Earth absorption

Authors: IceCube Collaboration, M. G. Aartsen, M. Ackermann, J. Adams, J. A. Aguilar, M. Ahlers, M. Ahrens, I. Al Samarai, D. Altmann, K. Andeen, T. Anderson, I. Ansseau, G. Anton, C. Argüelles, J. Auffenberg, S. Axani, H. Bagherpour, X. Bai, J. P. Barron, S. W. Barwick, V. Baum, R. Bay, J. J. Beatty, J. Becker Tjus, K. -H. Becker , et al. (293 additional authors not shown)

Abstract: Neutrinos interact only very weakly, so they are extremely penetrating. However, the theoretical neutrino-nucleon interaction cross section rises with energy such that, at energies above 40 TeV, neutrinos are expected to be absorbed as they pass through the Earth. Experimentally, the cross section has been measured only at the relatively low energies (below 400 GeV) available at neutrino beams fro… ▽ More Neutrinos interact only very weakly, so they are extremely penetrating. However, the theoretical neutrino-nucleon interaction cross section rises with energy such that, at energies above 40 TeV, neutrinos are expected to be absorbed as they pass through the Earth. Experimentally, the cross section has been measured only at the relatively low energies (below 400 GeV) available at neutrino beams from accelerators \cite{Agashe:2014kda, Formaggio:2013kya}. Here we report the first measurement of neutrino absorption in the Earth, using a sample of 10,784 energetic upward-going neutrino-induced muons observed with the IceCube Neutrino Observatory. The flux of high-energy neutrinos transiting long paths through the Earth is attenuated compared to a reference sample that follows shorter trajectories through the Earth. Using a fit to the two-dimensional distribution of muon energy and zenith angle, we determine the cross section for neutrino energies between 6.3 TeV and 980 TeV, more than an order of magnitude higher in energy than previous measurements. The measured cross section is $1.30^{+0.21}_{-0.19}$ (stat.) $^{+0.39}_{-0.43}$ (syst.) times the prediction of the Standard Model \cite{CooperSarkar:2011pa}, consistent with the expectation for charged and neutral current interactions. We do not observe a dramatic increase in the cross section, expected in some speculative models, including those invoking new compact dimensions \cite{AlvarezMuniz:2002ga} or the production of leptoquarks \cite{Romero:2009vu}. △ Less

Submitted 21 November, 2017; originally announced November 2017.

Comments: Preprint version of Nature paper 10.1038/nature24459

Journal ref: Nature 551 (2017) 596-600

A Model for the Global Quantum Efficiency for a TPB-based Wavelength-Shifting System used with Photomultiplier Tubes in Liquid Argon in MicroBooNE

Authors: S. F. Pate, T. Wester, L. Bugel, J. Conrad, E. Henderson, B. J. P. Jones, A. I. L. McLean, J. S. Moon, M. Toups, T. Wongjirad

Abstract: We present a model for the Global Quantum Efficiency (GQE) of the MicroBooNE optical units. An optical unit consists of a flat, circular acrylic plate, coated with tetraphenyl butadiene (TPB), positioned near the photocathode of a 20.2-cm diameter photomultiplier tube. The plate converts the ultra-violet scintillation photons from liquid argon into visible-spectrum photons to which the cryogenic p… ▽ More We present a model for the Global Quantum Efficiency (GQE) of the MicroBooNE optical units. An optical unit consists of a flat, circular acrylic plate, coated with tetraphenyl butadiene (TPB), positioned near the photocathode of a 20.2-cm diameter photomultiplier tube. The plate converts the ultra-violet scintillation photons from liquid argon into visible-spectrum photons to which the cryogenic phototubes are sensitive. The GQE is the convolution of the efficiency of the plates that convert the 128 nm scintillation light from liquid argon to visible light, the efficiency of the shifted light to reach the photocathode, and the efficiency of the cryogenic photomultiplier tube. We develop a GEANT4-based model of the optical unit, based on first principles, and obtain the range of probable values for the expected number of detected photoelectrons ($N_{\rm PE}$) given the known systematic errors on the simulation parameters. We compare results from four measurements of the $N_{\rm PE}$ determined using alpha-particle sources placed at two distances from a TPB-coated plate in a liquid argon cryostat test stand. We also directly measured the radial dependence of the quantum efficiency, and find that this has the same shape as predicted by our model. Our model results in a GQE of $0.0055\pm0.0009$ for the MicroBooNE optical units. While the information shown here is MicroBooNE specific, the approach to the model and the collection of simulation parameters will be widely applicable to many liquid-argon-based light collection systems. △ Less

Submitted 5 March, 2018; v1 submitted 3 November, 2017; originally announced November 2017.

Comments: final version accepted for publication by JINST

Journal ref: Journal of Instrumentation, Volume 13, P02034, 2018

Search for Two-Neutrino Double Electron Capture of $^{124}$Xe with XENON100

Authors: The XENON Collaboration, E. Aprile, J. Aalbers, F. Agostini, M. Alfonsi, F. D. Amaro, M. Anthony, F. Arneodo, P. Barrow, L. Baudis, B. Bauermeister, M. L. Benabderrahmane, T. Berger, P. A. Breur, A. Brown, E. Brown, S. Bruenner, G. Bruno, R. Budnik, L. Bütikofer, J. Calvén, J. M. R. Cardoso, M. Cervantes, D. Cichon, D. Coderre , et al. (92 additional authors not shown)

Abstract: Two-neutrino double electron capture is a rare nuclear decay where two electrons are simultaneously captured from the atomic shell. For $^{124}$Xe this process has not yet been observed and its detection would provide a new reference for nuclear matrix element calculations. We have conducted a search for two-neutrino double electron capture from the K-shell of $^{124}$Xe using 7636 kg$\cdot$d of d… ▽ More Two-neutrino double electron capture is a rare nuclear decay where two electrons are simultaneously captured from the atomic shell. For $^{124}$Xe this process has not yet been observed and its detection would provide a new reference for nuclear matrix element calculations. We have conducted a search for two-neutrino double electron capture from the K-shell of $^{124}$Xe using 7636 kg$\cdot$d of data from the XENON100 dark matter detector. Using a Bayesian analysis we observed no significant excess above background, leading to a lower 90 % credibility limit on the half-life $T_{1/2}>6.5\times10^{20}$ yr. We also evaluated the sensitivity of the XENON1T experiment, which is currently being commissioned, and find a sensitivity of $T_{1/2}>6.1\times10^{22}$ yr after an exposure of 2 t$\cdot$yr. △ Less

Submitted 16 February, 2017; v1 submitted 12 September, 2016; originally announced September 2016.

Comments: 6 pages, 4 figures

Journal ref: Phys. Rev. C 95, 024605, Published 13 February 2017

Muon capture on light isotopes in Double Chooz

Authors: Double Chooz collaboration, Y. Abe, T. Abrahão, H. Almazan, C. Alt, S. Appel, J. C. Barriere, E. Baussan, I. Bekman, M. Bergevin, T. J. C. Bezerra, L. Bezrukov, E. Blucher, T. Brugière, C. Buck, J. Busenitz, A. Cabrera, L. Camilleri, R. Carr, M. Cerrada, E. Chauveau, P. Chimenti, A. P. Collin, E. Conover, J. M. Conrad , et al. (122 additional authors not shown)

Abstract: Using the Double Chooz detector, designed to measure the neutrino mixing angle $θ_{13}$, the products of $μ^-$ capture on $^{12}$C, $^{13}$C, $^{14}$N and $^{16}$O have been measured. Over a period of 489.5 days, $2.3\times10^6$ stopping cosmic $μ^-$ have been collected, of which $1.8\times10^5$ captured on carbon, nitrogen, or oxygen nuclei in the inner detector scintillator or acrylic vessels. T… ▽ More Using the Double Chooz detector, designed to measure the neutrino mixing angle $θ_{13}$, the products of $μ^-$ capture on $^{12}$C, $^{13}$C, $^{14}$N and $^{16}$O have been measured. Over a period of 489.5 days, $2.3\times10^6$ stopping cosmic $μ^-$ have been collected, of which $1.8\times10^5$ captured on carbon, nitrogen, or oxygen nuclei in the inner detector scintillator or acrylic vessels. The resulting isotopes were tagged using prompt neutron emission (when applicable), the subsequent beta decays, and, in some cases, $β$-delayed neutrons. The most precise measurement of the rate of $^{12}\mathrm C(μ^-,ν)^{12}\mathrm B$ to date is reported: $6.57^{+0.11}_{-0.21}\times10^{3}\,\mathrm s^{-1}$, or $(17.35^{+0.35}_{-0.59})\%$ of nuclear captures. By tagging excited states emitting gammas, the ground state transition rate to $^{12}$B has been determined to be $5.68^{+0.14}_{-0.23}\times10^3\,\mathrm s^{-1}$. The heretofore unobserved reactions $^{12}\mathrm C(μ^-,να)^{8}\mathrm{Li}$, $^{13}\mathrm C(μ^-,ν\mathrm nα)^{8}\mathrm{Li}$, and $^{13}\mathrm C(μ^-,ν\mathrm n)^{12}\mathrm B$ are measured. Further, a population of $β$n decays following stopping muons is identified with $5.5σ$ significance. Statistics limit our ability to identify these decays definitively. Assuming negligible production of $^{8}$He, the reaction $^{13}\mathrm C(μ^-,να)^{9}\mathrm{Li}$ is found to be present at the $2.7σ$ level. Limits are set on a variety of other processes. △ Less

Submitted 17 May, 2016; v1 submitted 23 December, 2015; originally announced December 2015.

Comments: 21 pages, 14 figures. Minor revisions. Corresponding author: M. Strait

Journal ref: Phys. Rev. C 93, 054608 (2016)

The Intermediate Neutrino Program

Authors: C. Adams, J. R. Alonso, A. M. Ankowski, J. A. Asaadi, J. Ashenfelter, S. N. Axani, K. Babu, C. Backhouse, H. R. Band, P. S. Barbeau, N. Barros, A. Bernstein, M. Betancourt, M. Bishai, E. Blucher, J. Bouffard, N. Bowden, S. Brice, C. Bryan, L. Camilleri, J. Cao, J. Carlson, R. E. Carr, A. Chatterjee, M. Chen , et al. (164 additional authors not shown)

Abstract: The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermedia… ▽ More The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop. △ Less

Submitted 1 April, 2015; v1 submitted 23 March, 2015; originally announced March 2015.

Comments: pdfLaTeX, 31 pages, 1 figure, minor modification to 0nuBB discussion

Advanced Scintillator Detector Concept (ASDC): A Concept Paper on the Physics Potential of Water-Based Liquid Scintillator

Authors: J. R. Alonso, N. Barros, M. Bergevin, A. Bernstein, L. Bignell, E. Blucher, F. Calaprice, J. M. Conrad, F. B. Descamps, M. V. Diwan, D. A. Dwyer, S. T. Dye, A. Elagin, P. Feng, C. Grant, S. Grullon, S. Hans, D. E. Jaffe, S. H. Kettell, J. R. Klein, K. Lande, J. G. Learned, K. B. Luk, J. Maricic, P. Marleau , et al. (25 additional authors not shown)

Abstract: The recent development of Water-based Liquid Scintillator (WbLS), and the concurrent development of high-efficiency and high-precision-timing light sensors, has opened up the possibility for a new kind of large-scale detector capable of a very broad program of physics. The program would include determination of the neutrino mass hierarchy and observation of CP violation with long-baseline neutrino… ▽ More The recent development of Water-based Liquid Scintillator (WbLS), and the concurrent development of high-efficiency and high-precision-timing light sensors, has opened up the possibility for a new kind of large-scale detector capable of a very broad program of physics. The program would include determination of the neutrino mass hierarchy and observation of CP violation with long-baseline neutrinos, searches for proton decay, ultra-precise solar neutrino measurements, geo- and supernova neutrinos including diffuse supernova antineutrinos, and neutrinoless double beta decay. We outline here the basic requirements of the Advanced Scintillation Detector Concept (ASDC), which combines the use of WbLS, doping with a number of potential isotopes for a range of physics goals, high efficiency and ultra-fast timing photosensors, and a deep underground location. We are considering such a detector at the Long Baseline Neutrino Facility (LBNF) far site, where the ASDC could operate in conjunction with the liquid argon tracking detector proposed by the LBNE collaboration. The goal is the deployment of a 30-100 kiloton-scale detector, the basic elements of which are being developed now in experiments such as WATCHMAN, ANNIE, SNO+, and EGADS. △ Less

Submitted 24 October, 2014; v1 submitted 20 September, 2014; originally announced September 2014.

Report number: BNL-106082-2014-JA

Using L/E Oscillation Probability Distributions

Authors: A. A. Aguilar-Arevalo, B. C. Brown, L. Bugel, G. Cheng, E. D. Church, J. M. Conrad, R. Dharmapalan, Z. Djurcic, D. A. Finley, R. Ford, F. G. Garcia, G. T. Garvey, J. Grange, W. Huelsnitz, C. Ignarra, R. Imlay, R. A. Johnson, G. Karagiorgi, T. Katori, T. Kobilarcik, W. C. Louis, C. Mariani, W. Marsh, G. B. Mills, J. Mirabal , et al. (19 additional authors not shown)

Abstract: This paper explores the use of $L/E$ oscillation probability distributions to compare experimental measurements and to evaluate oscillation models. In this case, $L$ is the distance of neutrino travel and $E$ is a measure of the interacting neutrino's energy. While comparisons using allowed and excluded regions for oscillation model parameters are likely the only rigorous method for these comparis… ▽ More This paper explores the use of $L/E$ oscillation probability distributions to compare experimental measurements and to evaluate oscillation models. In this case, $L$ is the distance of neutrino travel and $E$ is a measure of the interacting neutrino's energy. While comparisons using allowed and excluded regions for oscillation model parameters are likely the only rigorous method for these comparisons, the $L/E$ distributions are shown to give qualitative information on the agreement of an experiment's data with a simple two-neutrino oscillation model. In more detail, this paper also outlines how the $L/E$ distributions can be best calculated and used for model comparisons. Specifically, the paper presents the $L/E$ data points for the final MiniBooNE data samples and, in the Appendix, explains and corrects the mistaken analysis published by the ICARUS collaboration. △ Less

Submitted 11 July, 2014; originally announced July 2014.

Precision $\bar ν_e$-electron Scattering Measurements with IsoDAR to Search for New Physics

Authors: J. M. Conrad, M. H. Shaevitz, I. Shimizu, J. Spitz, M. Toups, L. Winslow

Abstract: IsoDAR provides a pure and intense $\bar ν_e$ source with an average energy of 6.5 MeV produced through $^8$Li $β$-decay. This source can be paired with a large scintillator detector, such as KamLAND, to produce a sample of $\bar ν_e$-electron scatters that is more than five times larger than what has been collected before. Such a sample would allow for a 3.2% measurement of $\sin^2θ_W$ and a sens… ▽ More IsoDAR provides a pure and intense $\bar ν_e$ source with an average energy of 6.5 MeV produced through $^8$Li $β$-decay. This source can be paired with a large scintillator detector, such as KamLAND, to produce a sample of $\bar ν_e$-electron scatters that is more than five times larger than what has been collected before. Such a sample would allow for a 3.2% measurement of $\sin^2θ_W$ and a sensitive search for non-standard interactions. △ Less

Submitted 30 September, 2013; v1 submitted 18 July, 2013; originally announced July 2013.

Comments: Added references

Journal ref: Phys. Rev. D 89, 072010 (2014)

The LSND and MiniBooNE Oscillation Searches at High $Δm^2$

Authors: Janet M. Conrad, William C. Louis, Michael H. Shaevitz

Abstract: This paper reviews the results of the LSND and MiniBooNE experiments. The primary goal of each experiment was to effect sensitive searches for neutrino oscillations in the mass region with $Δm^2 \sim 1$ eV$^2$. The two experiments are complementary, and so the comparison of results can bring additional information with respect to models with sterile neutrinos. Both experiments obtained evidence fo… ▽ More This paper reviews the results of the LSND and MiniBooNE experiments. The primary goal of each experiment was to effect sensitive searches for neutrino oscillations in the mass region with $Δm^2 \sim 1$ eV$^2$. The two experiments are complementary, and so the comparison of results can bring additional information with respect to models with sterile neutrinos. Both experiments obtained evidence for $\bar ν_μ\rightarrow \bar ν_e$ oscillations, and MiniBooNE also observed a $ν_μ\rightarrow ν_e$ excess. In this paper, we review the design, analysis, and results from these experiments. We then consider the results within the global context of sterile neutrino oscillation models. The final data sets require a more extended model than the simple single sterile neutrino model imagined at the time that LSND drew to a close and MiniBooNE began. We show that there are apparent incompatibilities between data sets in models with two sterile neutrinos. However, these incompatibilities may be explained with variations within the systematic error. Overall, models with two (or three) sterile neutrinos seem to succeed in fitting the global data, and they make interesting predictions for future experiments. △ Less

Submitted 27 June, 2013; originally announced June 2013.

Comments: Posted with permission from the Annual Review of Nuclear and Particle Science, Volume 63. \c{opyright} 2013 by Annual Reviews, http://www.annualreviews.org

Journal ref: Annu. Rev. Nucl. Part. Sci. 63, 45 (2013)

Improved Search for $\bar ν_μ\rightarrow \bar ν_e$ Oscillations in the MiniBooNE Experiment

Authors: The MiniBooNE Collaboration, A. A. Aguilar-Arevalo, B. C. Brown, L. Bugel, G. Cheng, E. D. Church, J. M. Conrad, R. Dharmapalan, Z. Djurcic, D. A. Finley, R. Ford, F. G. Garcia, G. T. Garvey, J. Grange, W. Huelsnitz, C. Ignarra, R. Imlay, R. A. Johnson, G. Karagiorgi, T. Katori, T. Kobilarcik, W. C. Louis, C. Mariani, W. Marsh, G. B. Mills , et al. (20 additional authors not shown)

Abstract: The MiniBooNE experiment at Fermilab reports results from an analysis of $\bar ν_e$ appearance data from $11.27 \times 10^{20}$ protons on target in antineutrino mode, an increase of approximately a factor of two over the previously reported results. An event excess of $78.4 \pm 28.5$ events ($2.8 σ$) is observed in the energy range $200<E_ν^{QE}<1250$ MeV. If interpreted in a two-neutrino oscilla… ▽ More The MiniBooNE experiment at Fermilab reports results from an analysis of $\bar ν_e$ appearance data from $11.27 \times 10^{20}$ protons on target in antineutrino mode, an increase of approximately a factor of two over the previously reported results. An event excess of $78.4 \pm 28.5$ events ($2.8 σ$) is observed in the energy range $200<E_ν^{QE}<1250$ MeV. If interpreted in a two-neutrino oscillation model, $\barν_μ\rightarrow\barν_e$, the best oscillation fit to the excess has a probability of 66% while the background-only fit has a $χ^2$-probability of 0.5% relative to the best fit. The data are consistent with antineutrino oscillations in the $0.01 < Δm^2 < 1.0$ eV$^2$ range and have some overlap with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector (LSND). All of the major backgrounds are constrained by in-situ event measurements so non-oscillation explanations would need to invoke new anomalous background processes. The neutrino mode running also shows an excess at low energy of $162.0 \pm 47.8$ events ($3.4 σ$) but the energy distribution of the excess is marginally compatible with a simple two neutrino oscillation formalism. Expanded models with several sterile neutrinos can reduce the incompatibility by allowing for CP violating effects between neutrino and antineutrino oscillations. △ Less

Submitted 12 March, 2013; v1 submitted 11 March, 2013; originally announced March 2013.

Comments: Submitted to PRL. Further information provided in arXiv:1207.4809

Report number: LA-UR-13-21523

Cost-effective Design Options for IsoDAR

Authors: A. Adelmann, J. R. Alonso, W. Barletta, R. Barlow, L. Bartoszek, A. Bungau, L. Calabretta, A. Calanna, D. Campo, J. M. Conrad, Z. Djurcic, Y. Kamyshkov, H. Owen, M. H. Shaevitz, I. Shimizu, T. Smidt, J. Spitz, M. Toups, M. Wascko, L. A. Winslow, J. J. Yang

Abstract: This whitepaper reviews design options for the IsoDAR electron antineutrino source. IsoDAR is designed to produce $2.6 \times 10^{22}$ electron antineutrinos per year with an average energy of 6.4 MeV, using isotope decay-at-rest. Aspects which must be balanced for cost-effectiveness include: overall cost; rate and energy distribution of the electron antineutrino flux and backgrounds; low technica… ▽ More This whitepaper reviews design options for the IsoDAR electron antineutrino source. IsoDAR is designed to produce $2.6 \times 10^{22}$ electron antineutrinos per year with an average energy of 6.4 MeV, using isotope decay-at-rest. Aspects which must be balanced for cost-effectiveness include: overall cost; rate and energy distribution of the electron antineutrino flux and backgrounds; low technical risk; compactness; simplicity of underground construction and operation; reliability; value to future neutrino physics programs; and value to industry. We show that the baseline design outlined here is the most cost effective. △ Less

Submitted 16 October, 2012; originally announced October 2012.

Comments: 33 pages, 11 figures

Direct Measurement of Backgrounds using Reactor-Off Data in Double Chooz

Authors: Y. Abe, C. Aberle, J. C. dos Anjos, J. C. Barriere, M. Bergevin, A. Bernstein, T. J. C. Bezerra, L. Bezrukhov, E. Blucher, N. S. Bowden, C. Buck, J. Busenitz, A. Cabrera, E. Caden, L. Camilleri, R. Carr, M. Cerrada, P. -J. Chang, P. Chimenti, T. Classen, A. P. Collin, E. Conover, J. M. Conrad, J. I. Crespo-Anadon, K. Crum , et al. (148 additional authors not shown)

Abstract: Double Chooz is unique among modern reactor-based neutrino experiments studying $\bar ν_e$ disappearance in that data can be collected with all reactors off. In this paper, we present data from 7.53 days of reactor-off running. Applying the same selection criteria as used in the Double Chooz reactor-on oscillation analysis, a measured background rate of 1.0$\pm$0.4 events/day is obtained. The back… ▽ More Double Chooz is unique among modern reactor-based neutrino experiments studying $\bar ν_e$ disappearance in that data can be collected with all reactors off. In this paper, we present data from 7.53 days of reactor-off running. Applying the same selection criteria as used in the Double Chooz reactor-on oscillation analysis, a measured background rate of 1.0$\pm$0.4 events/day is obtained. The background model for accidentals, cosmogenic $β$-$n$-emitting isotopes, fast neutrons from cosmic muons, and stopped-$μ$ decays used in the oscillation analysis is demonstrated to be correct within the uncertainties. Kinematic distributions of the events, which are dominantly cosmic-ray-produced correlated-background events, are provided. The background rates are scaled to the shielding depths of two other reactor-based oscillation experiments, Daya Bay and RENO. △ Less

Submitted 20 October, 2012; v1 submitted 13 October, 2012; originally announced October 2012.

Comments: V2 has corrections to affiliations

Letter of Intent: A new investigation of numu to nue oscillations with improved sensitivity in an enhanced MiniBooNE experiment

Authors: A. A. Aguilar-Arevalo, B. C. Brown, L. Bugel, R. Cooper, J. M. Conrad, R. Dharmapalan, R. Ford, Z. Djurcic, F. G. Garcia, G. T. Garvey, J. Grange, S. Habib, W. Huelsnitz, R. Imlay, C. Jiang, G. Karagiorgi, W. C. Louis, R. A. Johnson, W. Marsh, C. Mauger, G. B. Mills, C. D. Moore, J. Mousseau, P. Nienaber, B. Osmanov , et al. (11 additional authors not shown)

Abstract: We propose adding 300 mg/l PPO to the existing MiniBooNE detector mineral oil to increase the scintillation response. This will allow the detection of associated neutrons and increase sensitivity to final-state nucleons in neutrino interactions. This increased capability will enable an independent test of whether the current excess seen in the MiniBooNE oscillation search is signal or background.… ▽ More We propose adding 300 mg/l PPO to the existing MiniBooNE detector mineral oil to increase the scintillation response. This will allow the detection of associated neutrons and increase sensitivity to final-state nucleons in neutrino interactions. This increased capability will enable an independent test of whether the current excess seen in the MiniBooNE oscillation search is signal or background. In addition it will enable other neutrino interaction measurements to be made including a search for the strange-quark contribution to the nucleon spin Delta s and a low-energy measurement of charged-current quasielastic scattering. △ Less

Submitted 8 October, 2012; originally announced October 2012.

Comments: 27 pages, 12 figures, Letter of intent submitted to Fermilab for consideration, 10/12

A Combined $ν_μ\to ν_e$ and $\barν_μ\to \barν_e$ Oscillation Analysis of the MiniBooNE Excesses

Authors: MiniBooNE Collaboration, A. A. Aguilar-Arevalo, B. C. Brown, L. Bugel, G. Cheng, E. D. Church, J. M. Conrad, R. Dharmapalan, Z. Djurcic, D. A. Finley, R. Ford, F. G. Garcia, G. T. Garvey, J. Grange, W. Huelsnitz, C. Ignarra, R. Imlay, R. A. Johnson, G. Karagiorgi, T. Katori, T. Kobilarcik, W. C. Louis, C. Mariani, W. Marsh, G. B. Mills , et al. (20 additional authors not shown)

Abstract: The MiniBooNE experiment at Fermilab reports results from an analysis of the combined $ν_e$ and $\bar ν_e$ appearance data from $6.46 \times 10^{20}$ protons on target in neutrino mode and $11.27 \times 10^{20}$ protons on target in antineutrino mode. A total excess of $240.3 \pm 34.5 \pm 52.6$ events ($3.8 σ$) is observed from combining the two data sets in the energy range $200<E_ν^{QE}<1250$ Me… ▽ More The MiniBooNE experiment at Fermilab reports results from an analysis of the combined $ν_e$ and $\bar ν_e$ appearance data from $6.46 \times 10^{20}$ protons on target in neutrino mode and $11.27 \times 10^{20}$ protons on target in antineutrino mode. A total excess of $240.3 \pm 34.5 \pm 52.6$ events ($3.8 σ$) is observed from combining the two data sets in the energy range $200<E_ν^{QE}<1250$ MeV. In a combined fit for CP-conserving $ν_μ\rightarrow ν_e$ and $\barν_μ\rightarrow\barν_e$ oscillations via a two-neutrino model, the background-only fit has a $χ^2$-probability of 0.03% relative to the best oscillation fit. The data are consistent with neutrino oscillations in the $0.01 < Δm^2 < 1.0$ eV$^2$ range and with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector (LSND). △ Less

Submitted 27 August, 2012; v1 submitted 19 July, 2012; originally announced July 2012.

Comments: Minor wording and figure changes and added references

Report number: LA-UR-12-23041; Fermilab-PUB-12-394-AD-PPD

Target Studies for the Production of Lithium8 for Neutrino Physics Using a Low Energy Cyclotron

Authors: Adriana Bungau, Roger Barlow, Michael Shaevitz, Janet Conrad, Joshua Spitz

Abstract: Lithium 8 is a short lived beta emitter producing a high energy anti-neutrino, which is very suitable for making several measurements of fundamental quantities. It is proposed to produce Lithium 8 with a commercially available 60 MeV cyclotron using protons or alpha particles on a Beryllium 9 target. We have used the GEANT4 program to model these processes, and calculate the anti-neutrino fluxes t… ▽ More Lithium 8 is a short lived beta emitter producing a high energy anti-neutrino, which is very suitable for making several measurements of fundamental quantities. It is proposed to produce Lithium 8 with a commercially available 60 MeV cyclotron using protons or alpha particles on a Beryllium 9 target. We have used the GEANT4 program to model these processes, and calculate the anti-neutrino fluxes that could be obtained in a practical system. We also calculate the production of undesirable contaminants such as Boron 8, and show that these can be reduced to a very low level. △ Less

Submitted 25 May, 2012; originally announced May 2012.

Comments: 3 pages, 6 figures, IPAC 2012

Proposal for an Electron Antineutrino Disappearance Search Using High-Rate 8Li Production and Decay

Authors: A. Bungau, A. Adelmann, J. R. Alonso, W. Barletta, R. Barlow, L. Bartoszek, L. Calabretta, A. Calanna, D. Campo, J. M. Conrad, Z. Djurcic, Y. Kamyshkov, M. H. Shaevitz, I. Shimizu, T. Smidt, J. Spitz, M. Wascko, L. A. Winslow, J. J. Yang

Abstract: This paper introduces a novel, high-intensity source of electron antineutrinos from the production and subsequent decay of 8Li. When paired with an existing ~1 kton scintillator-based detector, this <E_ν>=6.4 MeV source opens a wide range of possible searches for beyond standard model physics via studies of the inverse beta decay interaction. In particular, the experimental design described here h… ▽ More This paper introduces a novel, high-intensity source of electron antineutrinos from the production and subsequent decay of 8Li. When paired with an existing ~1 kton scintillator-based detector, this <E_ν>=6.4 MeV source opens a wide range of possible searches for beyond standard model physics via studies of the inverse beta decay interaction. In particular, the experimental design described here has unprecedented sensitivity to electron antineutrino disappearance at $Δm^2\sim$ 1 eV$^2$ and features the ability to distinguish between the existence of zero, one, and two sterile neutrinos. △ Less

Submitted 22 December, 2012; v1 submitted 20 May, 2012; originally announced May 2012.

Comments: 5 pages, 4 figures; (new version after PRL referee's comments)

Light Sterile Neutrinos: A White Paper

Authors: K. N. Abazajian, M. A. Acero, S. K. Agarwalla, A. A. Aguilar-Arevalo, C. H. Albright, S. Antusch, C. A. Arguelles, A. B. Balantekin, G. Barenboim, V. Barger, P. Bernardini, F. Bezrukov, O. E. Bjaelde, S. A. Bogacz, N. S. Bowden, A. Boyarsky, A. Bravar, D. Bravo Berguno, S. J. Brice, A. D. Bross, B. Caccianiga, F. Cavanna, E. J. Chun, B. T. Cleveland, A. P. Collin , et al. (162 additional authors not shown)

Abstract: This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data. This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data. △ Less

Submitted 18 April, 2012; originally announced April 2012.

Reactor Simulation for Antineutrino Experiments using DRAGON and MURE

Authors: C. L. Jones, A. Bernstein, J. M. Conrad, Z. Djurcic, M. Fallot, L. Giot, G. Keefer, A. Onillon, L. Winslow

Abstract: Rising interest in nuclear reactors as a source of antineutrinos for experiments motivates validated, fast, and accessible simulations to predict reactor fission rates. Here we present results from the DRAGON and MURE simulation codes and compare them to other industry standards for reactor core modeling. We use published data from the Takahama-3 reactor to evaluate the quality of these simulation… ▽ More Rising interest in nuclear reactors as a source of antineutrinos for experiments motivates validated, fast, and accessible simulations to predict reactor fission rates. Here we present results from the DRAGON and MURE simulation codes and compare them to other industry standards for reactor core modeling. We use published data from the Takahama-3 reactor to evaluate the quality of these simulations against the independently measured fuel isotopic composition. The propagation of the uncertainty in the reactor operating parameters to the resulting antineutrino flux predictions is also discussed. △ Less

Submitted 4 June, 2012; v1 submitted 25 September, 2011; originally announced September 2011.

Comments: This version has increased discussion of uncertainties

A Prototype Detector for Directional Measurement of the Cosmogenic Neutron Flux

Authors: J. Lopez, K. Terao, J. M. Conrad, D. Dujmic, L. Winslow

Abstract: This paper describes a novel directional neutron detector prototype. The low pressure time projection chamber uses a mix of helium and CF4 gases. The detector reconstructs the energy and angular distribution of fast neutron recoils. This paper reports results of energy calibration using an alpha source and angular reconstruction studies using a collimated neutron source. The best performance is ob… ▽ More This paper describes a novel directional neutron detector prototype. The low pressure time projection chamber uses a mix of helium and CF4 gases. The detector reconstructs the energy and angular distribution of fast neutron recoils. This paper reports results of energy calibration using an alpha source and angular reconstruction studies using a collimated neutron source. The best performance is obtained with a 12.5% CF4 gas mixture. At low energies the target for fast neutrons transitions is primarily helium, while at higher energies, the fluorine contributes as a target. The reconstruction efficiency is both energy and target dependent. For neutrons with energies less than 20 MeV, the reconstruction efficiency is ~40% for fluorine recoils and ~60% for helium recoils. △ Less

Submitted 17 January, 2013; v1 submitted 24 August, 2011; originally announced August 2011.

Comments: final version

Journal ref: NIM A 673, 22-31 (2012)

Measurement of $ν_μ$-induced charged-current neutral pion production cross sections on mineral oil at $E_ν\in0.5-2.0$ GeV

Authors: A. A. Aguilar-Arevalo, C. E. Anderson, A. O. Bazarko, S. J. Brice, B. C. Brown, L. Bugel, J. Cao, L. Coney, J. M. Conrad, D. C. Cox, A. Curioni, R. Dharmapalan, Z. Djurcic, D. A. Finley, B. T. Fleming, R. Ford, F. G. Garcia, G. T. Garvey, J. Grange, C. Green, J. A. Green, T. L. Hart, E. Hawker, R. Imlay, R. A. Johnson , et al. (61 additional authors not shown)

Abstract: Using a custom 3 Čerenkov-ring fitter, we report cross sections for $ν_μ$-induced charged-current single $π^0$ production on mineral oil (\chtwo) from a sample of 5810 candidate events with 57% signal purity over an energy range of $0.5-2.0$GeV. This includes measurements of the absolute total cross section as a function of neutrino energy, and flux-averaged differential cross sections measured in… ▽ More Using a custom 3 Čerenkov-ring fitter, we report cross sections for $ν_μ$-induced charged-current single $π^0$ production on mineral oil (\chtwo) from a sample of 5810 candidate events with 57% signal purity over an energy range of $0.5-2.0$GeV. This includes measurements of the absolute total cross section as a function of neutrino energy, and flux-averaged differential cross sections measured in terms of $Q^2$, $μ^-$ kinematics, and $π^0$ kinematics. The sample yields a flux-averaged total cross section of $(9.2\pm0.3_{stat.}\pm1.5_{syst.})\times10^{-39}$cm$^2$/CH$_2$ at mean neutrino energy of 0.965GeV. △ Less

Submitted 10 February, 2011; v1 submitted 15 October, 2010; originally announced October 2010.

Comments: 21 pages, 14 figures, and 11 tables

Journal ref: Phys.Rev.D83:052009,2011

Measurement of neutral current coherent neutral pion production on carbon in a few-GeV neutrino beam

Authors: Y. Kurimoto, J. L. Alcaraz-Aunion, S. J. Brice, L. Bugel, J. Catala-Perez, G. Cheng, J. M. Conrad, Z. Djurcic, U. Dore, D. A. Finley, A. J. Franke, C. Giganti, J. J. Gomez-Cadenas, P. Guzowski, A. Hanson, Y. Hayato, K. Hiraide, G. Jover-Manas, G. Karagiorgi, T. Katori, Y. K. Kobayashi, T. Kobilarcik, H. Kubo, W. C. Louis, P. F. Loverre , et al. (39 additional authors not shown)

Abstract: The SciBooNE Collaboration reports a measurement of neutral current coherent neutral pion production on carbon by a muon neutrino beam with average energy 0.8 GeV. The separation of coherent from inclusive neutral pion production has been improved by detecting recoil protons from resonant neutral pion production. We measure the ratio of the neutral current coherent neutral pion production to total… ▽ More The SciBooNE Collaboration reports a measurement of neutral current coherent neutral pion production on carbon by a muon neutrino beam with average energy 0.8 GeV. The separation of coherent from inclusive neutral pion production has been improved by detecting recoil protons from resonant neutral pion production. We measure the ratio of the neutral current coherent neutral pion production to total charged current cross sections to be (1.16 +/- 0.24) x 10-2. The ratio of charged current coherent pion to neutral current coherent pion production is calculated to be 0.14+0.30 -0.28, using our published charged current coherent pion measurement. △ Less

Submitted 1 May, 2010; originally announced May 2010.

Comments: seven pages, 6 fiures

Journal ref: Phys.Rev.D81:111102,2010

Beam Test Performance and Simulation of Prototypes for the ALICE Silicon Pixel Detector

Authors: Jan Conrad

Abstract: The silicon pixel detector (SPD) of the ALICE experiment in preparation at the Large Hadron Collider (LHC) at CERN is designed to provide the precise vertex reconstruction needed for measuring heavy flavor production in heavy ion collisions at very high energies and high multiplicity. The SPD forms the innermost part of the Inner Tracking System (ITS) which also includes silicon drift and silico… ▽ More The silicon pixel detector (SPD) of the ALICE experiment in preparation at the Large Hadron Collider (LHC) at CERN is designed to provide the precise vertex reconstruction needed for measuring heavy flavor production in heavy ion collisions at very high energies and high multiplicity. The SPD forms the innermost part of the Inner Tracking System (ITS) which also includes silicon drift and silicon strip detectors. Single assembly prototypes of the ALICE SPD have been tested at the CERN SPS using high energy proton/pion beams in 2002 and 2003. We report on the experimental determination of the spatial precision. We also report on the first combined beam test with prototypes of the other ITS silicon detector technologies at the CERN SPS in November 2004. The issue of SPD simulation is briefly discussed. △ Less

Submitted 7 November, 2005; originally announced November 2005.

Comments: 4 pages, 5 figures, prepared for proceedings of 7th International Position Sensitive Detectors Conference, Liverpool, Sept. 2005

Journal ref: Nucl.Instrum.Meth.A573:1-3,2007

A letter of intent for an experiment to measure nu_mu to nu_e oscillations and nu_mu disappearance at the Fermilab Booster (BooNE)

Authors: E. Church, I. Stancu, G. J. VanDalen, R. A. Johnson, J. M. Conrad, J. Formaggio, T. Ochs, M. H. Shaevitz, E. G. Stern, B. Tamminga, D. Smith, G. T. Garvey, W. C. Louis, G. B. Mills, V. Sandberg, R. Tayloe, D. H. White, H. J. Kim, R. Imlay, W. Metcalf, N. Wadia, Z. D. Greenwood

Abstract: This Letter of Intent to the Fermilab Program Advisory Committee describes a search for neutrino oscillations at the Fermilab booster. It is motivated by the LSND observation of nu_mu -> nu_e appearance. The booster neutrino experiment (BooNE) will be capable of observing both nu_mu -> nu_e appearance and nu_mu disappearance. In addition, the experiment will be able to measure Delta m^2 and sin^… ▽ More This Letter of Intent to the Fermilab Program Advisory Committee describes a search for neutrino oscillations at the Fermilab booster. It is motivated by the LSND observation of nu_mu -> nu_e appearance. The booster neutrino experiment (BooNE) will be capable of observing both nu_mu -> nu_e appearance and nu_mu disappearance. In addition, the experiment will be able to measure Delta m^2 and sin^2(2theta) and search for CP violation in the lepton sector. △ Less

Submitted 30 June, 1997; v1 submitted 27 June, 1997; originally announced June 1997.

Comments: Presented to Fermilab PAC June 17, 1997 LaTex, psfig Fig. 40 repaired 6-30-97

Report number: LA-UR-97-2120