Showing 1–32 of 32 results for author: Jones, D C

Measurement of the Parity-Violating Asymmetry in the N to $Δ$ Transition at Low $Q^2$

Authors: D. Adhikari, T. Alshayeb, D. Androic, D. S. Armstrong, A. Asaturyan, K. Bartlett, R. S. Beminiwattha, J. Benesch, F. Benmokhtar, R. D. Carlini, J. C. Cornejo, S. Covrig Dusa, M. M. Dalton, C. A. Davis, W. Deconinck, J. A. Dunne, D. Dutta, W. S. Duvall, M. Elaasar, W. R. Falk, J. M. Finn, C. Gal, D. Gaskell, M. T. W. Gericke, J. R. Hoskins , et al. (48 additional authors not shown)

Abstract: We report the measurement of the parity-violating asymmetry in the N to $Δ$ transition via the $e^- + p \rightarrow e^- + Δ^+$ reaction at two different kinematic points with low four-momentum transfer Q$^2$. Measurements were made with incident electron beam energies of 0.877 and 1.16 GeV, corresponding to $Q^2$ values of 0.0111 and 0.0208 (GeV/c)$^2$, respectively. These measurements put constra… ▽ More We report the measurement of the parity-violating asymmetry in the N to $Δ$ transition via the $e^- + p \rightarrow e^- + Δ^+$ reaction at two different kinematic points with low four-momentum transfer Q$^2$. Measurements were made with incident electron beam energies of 0.877 and 1.16 GeV, corresponding to $Q^2$ values of 0.0111 and 0.0208 (GeV/c)$^2$, respectively. These measurements put constraints on a low-energy constant in the weak Lagrangian, $d_Δ$, corresponding to a parity-violating electric-dipole transition matrix element. This matrix element has been shown to be large in the strangeness-changing channel, via weak hyperon decays such as $Σ^+ \rightarrow pγ$. The measurements reported here constrain $d_Δ$ in the strangeness-conserving channel. The final asymmetries were -0.65 +- 1.00 (stat.) +- 1.02 (syst) ppm (parts per million) for 0.877 GeV and -3.59 +- 0.82 (stat.) +- 1.33 (syst.} ppm for 1.16 GeV. With these results we deduce a small value for $d_Δ$, consistent with zero, in the strangeness-conserving channel, in contrast to the large value for $d_Δ$ previously reported in the strangeness-changing channel. △ Less

Submitted 24 April, 2025; originally announced April 2025.

Comments: 6 pages, 1 figure

Reactor Antineutrino Directionality Measurement with the PROSPECT-I Detector

Authors: M. Andriamirado, B. Balantekin, C. D. Bass, O. Benevides Rodrigues, E. P. Bernard, N. S. Bowden, C. D. Bryan, R. Carr, T. Classen, A. J. Conant, G. Deichert, M. J. Dolinski, A. Erickson, A. Galindo-Uribarri, S. Gokhale, C. Grant, S. Hans, A. B. Hansell, K. M. Heeger, B. Heffron, D. E. Jaffe, S. Jayakumar, D. C. Jones, J. R. Koblanski, P. Kunkle , et al. (24 additional authors not shown)

Abstract: The PROSPECT-I detector has several features that enable measurement of the direction of a compact neutrino source. In this paper, a detailed report on the directional measurements made on electron antineutrinos emitted from the High Flux Isotope Reactor is presented. With an estimated true neutrino (reactor to detector) direction of $φ= 40.8\unicode{xB0} \pm 0.7\unicode{xB0}$ and… ▽ More The PROSPECT-I detector has several features that enable measurement of the direction of a compact neutrino source. In this paper, a detailed report on the directional measurements made on electron antineutrinos emitted from the High Flux Isotope Reactor is presented. With an estimated true neutrino (reactor to detector) direction of $φ= 40.8\unicode{xB0} \pm 0.7\unicode{xB0}$ and $θ= 98.6\unicode{xB0} \pm 0.4\unicode{xB0}$, the PROSPECT-I detector is able to reconstruct an average neutrino direction of $φ= 39.4\unicode{xB0} \pm 2.9\unicode{xB0}$ and $θ= 97.6\unicode{xB0} \pm 1.6\unicode{xB0}$. This measurement is made with approximately 48000 Inverse Beta Decay signal events and is the most precise directional reconstruction of reactor antineutrinos to date. △ Less

Submitted 11 July, 2024; v1 submitted 12 June, 2024; originally announced June 2024.

`Maser-in-a-Shoebox': a portable plug-and-play maser device at room-temperature and zero magnetic-field

Authors: Wern Ng, Yongqiang Wen, Max Attwood, Daniel C Jones, Mark Oxborrow, Neil McN. Alford, Daan M. Arroo

Abstract: Masers, the microwave analogues of lasers, have seen a renaissance owing to the discovery of gain media that mase at room-temperature and zero-applied magnetic field. However, despite the ease with which the devices can be demonstrated under ambient conditions, achieving the ubiquity and portability which lasers enjoy has to date remained challenging. We present a maser device with a miniaturized… ▽ More Masers, the microwave analogues of lasers, have seen a renaissance owing to the discovery of gain media that mase at room-temperature and zero-applied magnetic field. However, despite the ease with which the devices can be demonstrated under ambient conditions, achieving the ubiquity and portability which lasers enjoy has to date remained challenging. We present a maser device with a miniaturized maser cavity, gain material and laser pump source that fits within the size of a shoebox. The gain medium used is pentacene-doped in para-terphenyl and it is shown to give a strong masing signal with a peak power of -5 dBm even within a smaller form factor. The device is also shown to mase at different frequencies within a small range of 1.5 MHz away from the resonant frequency. The portability and simplicity of the device, which weighs under 5 kg, paves the way for demonstrators particularly in the areas of low-noise amplifiers, quantum sensors, cavity quantum electrodynamics and long-range communications. △ Less

Submitted 13 October, 2023; originally announced October 2023.

Journal ref: Appl. Phys. Lett. 124, 044004 (2024)

Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab

Authors: A. Accardi, P. Achenbach, D. Adhikari, A. Afanasev, C. S. Akondi, N. Akopov, M. Albaladejo, H. Albataineh, M. Albrecht, B. Almeida-Zamora, M. Amaryan, D. Androić, W. Armstrong, D. S. Armstrong, M. Arratia, J. Arrington, A. Asaturyan, A. Austregesilo, H. Avagyan, T. Averett, C. Ayerbe Gayoso, A. Bacchetta, A. B. Balantekin, N. Baltzell, L. Barion , et al. (419 additional authors not shown)

Abstract: This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron… ▽ More This document presents the initial scientific case for upgrading the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) to 22 GeV. It is the result of a community effort, incorporating insights from a series of workshops conducted between March 2022 and April 2023. With a track record of over 25 years in delivering the world's most intense and precise multi-GeV electron beams, CEBAF's potential for a higher energy upgrade presents a unique opportunity for an innovative nuclear physics program, which seamlessly integrates a rich historical background with a promising future. The proposed physics program encompass a diverse range of investigations centered around the nonperturbative dynamics inherent in hadron structure and the exploration of strongly interacting systems. It builds upon the exceptional capabilities of CEBAF in high-luminosity operations, the availability of existing or planned Hall equipment, and recent advancements in accelerator technology. The proposed program cover various scientific topics, including Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic highlights the key measurements achievable at a 22 GeV CEBAF accelerator. Furthermore, this document outlines the significant physics outcomes and unique aspects of these programs that distinguish them from other existing or planned facilities. In summary, this document provides an exciting rationale for the energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific potential that lies within reach, and the remarkable opportunities it offers for advancing our understanding of hadron physics and related fundamental phenomena. △ Less

Submitted 24 August, 2023; v1 submitted 13 June, 2023; originally announced June 2023.

Comments: Updates to the list of authors; Preprint number changed from theory to experiment; Updates to sections 4 and 6, including additional figures

Report number: JLAB-PHY-23-3840

The Present and Future of QCD

Authors: P. Achenbach, D. Adhikari, A. Afanasev, F. Afzal, C. A. Aidala, A. Al-bataineh, D. K. Almaalol, M. Amaryan, D. Androić, W. R. Armstrong, M. Arratia, J. Arrington, A. Asaturyan, E. C. Aschenauer, H. Atac, H. Avakian, T. Averett, C. Ayerbe Gayoso, X. Bai, K. N. Barish, N. Barnea, G. Basar, M. Battaglieri, A. A. Baty, I. Bautista , et al. (378 additional authors not shown)

Abstract: This White Paper presents the community inputs and scientific conclusions from the Hot and Cold QCD Town Meeting that took place September 23-25, 2022 at MIT, as part of the Nuclear Science Advisory Committee (NSAC) 2023 Long Range Planning process. A total of 424 physicists registered for the meeting. The meeting highlighted progress in Quantum Chromodynamics (QCD) nuclear physics since the 2015… ▽ More This White Paper presents the community inputs and scientific conclusions from the Hot and Cold QCD Town Meeting that took place September 23-25, 2022 at MIT, as part of the Nuclear Science Advisory Committee (NSAC) 2023 Long Range Planning process. A total of 424 physicists registered for the meeting. The meeting highlighted progress in Quantum Chromodynamics (QCD) nuclear physics since the 2015 LRP (LRP15) and identified key questions and plausible paths to obtaining answers to those questions, defining priorities for our research over the coming decade. In defining the priority of outstanding physics opportunities for the future, both prospects for the short (~ 5 years) and longer term (5-10 years and beyond) are identified together with the facilities, personnel and other resources needed to maximize the discovery potential and maintain United States leadership in QCD physics worldwide. This White Paper is organized as follows: In the Executive Summary, we detail the Recommendations and Initiatives that were presented and discussed at the Town Meeting, and their supporting rationales. Section 2 highlights major progress and accomplishments of the past seven years. It is followed, in Section 3, by an overview of the physics opportunities for the immediate future, and in relation with the next QCD frontier: the EIC. Section 4 provides an overview of the physics motivations and goals associated with the EIC. Section 5 is devoted to the workforce development and support of diversity, equity and inclusion. This is followed by a dedicated section on computing in Section 6. Section 7 describes the national need for nuclear data science and the relevance to QCD research. △ Less

Submitted 4 March, 2023; originally announced March 2023.

Comments: QCD Town Meeting White Paper, as submitted to 2023 NSAC LRP committee on Feb. 28, 2023

Journal ref: Nucl.Phys.A 1047 (2024) 122874

Final Measurement of the U235 Antineutrino Energy Spectrum with the PROSPECT-I Detector at HFIR

Authors: M. Adriamirado, A. B. Balantekin, C. D. Bass, D. E. Bergeron, E. P. Bernard, N. S. Bowden, C. D. Bryan, R. Carr, T. Classen, A. J. Conant, G. Deichert, A. Delgado, M. V. Diwan, M. J. Dolinski, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribari, C. E. Gilbert, S. Gokhale, C. Grant, S. Hans, A. B. Hansell, K. M. Heeger, B. Heffron , et al. (39 additional authors not shown)

Abstract: This Letter reports one of the most precise measurements to date of the antineutrino spectrum from a purely U235-fueled reactor, made with the final dataset from the PROSPECT-I detector at the High Flux Isotope Reactor. By extracting information from previously unused detector segments, this analysis effectively doubles the statistics of the previous PROSPECT measurement. The reconstructed energy… ▽ More This Letter reports one of the most precise measurements to date of the antineutrino spectrum from a purely U235-fueled reactor, made with the final dataset from the PROSPECT-I detector at the High Flux Isotope Reactor. By extracting information from previously unused detector segments, this analysis effectively doubles the statistics of the previous PROSPECT measurement. The reconstructed energy spectrum is unfolded into antineutrino energy and compared with both the Huber-Mueller model and a spectrum from a commercial reactor burning multiple fuel isotopes. A local excess over the model is observed in the 5MeV to 7MeV energy region. Comparison of the PROSPECT results with those from commercial reactors provides new constraints on the origin of this excess, disfavoring at 2.2 and 3.2 standard deviations the hypotheses that antineutrinos from U235 are solely responsible and non-contributors to the excess observed at commercial reactors respectively. △ Less

Submitted 16 August, 2023; v1 submitted 20 December, 2022; originally announced December 2022.

Comments: The paper has been updated to match publication at PRL

Calibration strategy of the PROSPECT-II detector with external and intrinsic sources

Authors: M. Andriamirado, A. B. Balantekin, C. D. Bass, D. E. Bergeron, E. P. Bernard, N. S. Bowden, C. D. Bryan, R. Carr, T. Classen, A. J. Conant, A. Delgado, M. V. Diwan, M. J. Dolinski, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribarri, C. E. Gilbert, S. Gokhale, C. Grant, S. Hans, A. B. Hansell, K. M. Heeger, B. Heffron, D. E. Jaffe , et al. (36 additional authors not shown)

Abstract: This paper presents an energy calibration scheme for an upgraded reactor antineutrino detector for the Precision Reactor Oscillation and Spectrum Experiment (PROSPECT). The PROSPECT collaboration is preparing an upgraded detector, PROSPECT-II (P-II), to advance capabilities for the investigation of fundamental neutrino physics, fission processes and associated reactor neutrino flux, and nuclear se… ▽ More This paper presents an energy calibration scheme for an upgraded reactor antineutrino detector for the Precision Reactor Oscillation and Spectrum Experiment (PROSPECT). The PROSPECT collaboration is preparing an upgraded detector, PROSPECT-II (P-II), to advance capabilities for the investigation of fundamental neutrino physics, fission processes and associated reactor neutrino flux, and nuclear security applications. P-II will expand the statistical power of the original PROSPECT (P-I) dataset by at least an order of magnitude. The new design builds upon previous P-I design and focuses on improving the detector robustness and long-term stability to enable multi-year operation at one or more sites. The new design optimizes the fiducial volume by elimination of dead space previously occupied by internal calibration channels, which in turn necessitates the external deployment. In this paper, we describe a calibration strategy for P-II. The expected performance of externally deployed calibration sources is evaluated using P-I data and a well-benchmarked simulation package by varying detector segmentation configurations in the analysis. The proposed external calibration scheme delivers a compatible energy scale model and achieves comparable performance with the inclusion of an additional AmBe neutron source, in comparison to the previous internal arrangement. Most importantly, the estimated uncertainty contribution from the external energy scale calibration model meets the precision requirements of the P-II experiment. △ Less

Submitted 10 April, 2023; v1 submitted 17 November, 2022; originally announced November 2022.

Comments: 19 pages, 10 figures

Centrifugal Barrier and Super-Keplerian Rotation in Protostellar Disk Formation

Authors: Dylan C. Jones, Ka Ho Lam, Zhi-Yun Li, Yisheng Tu

Abstract: With the advent of ALMA, it is now possible to observationally constrain how disks form around deeply embedded protostars. In particular, the recent ALMA C3H2 line observations of the nearby protostar L1527 have been interpreted as evidence for the so-called "centrifugal barrier," where the protostellar envelope infall is gradually decelerated to a stop by the centrifugal force in a region of supe… ▽ More With the advent of ALMA, it is now possible to observationally constrain how disks form around deeply embedded protostars. In particular, the recent ALMA C3H2 line observations of the nearby protostar L1527 have been interpreted as evidence for the so-called "centrifugal barrier," where the protostellar envelope infall is gradually decelerated to a stop by the centrifugal force in a region of super-Keplerian rotation. To test the concept of centrifugal barrier, which was originally based on angular momentum conserving-collapse of a rotating test particle around a fixed point mass, we carry out simple axisymmetric hydrodynamic simulations of protostellar disk formation including a minimum set of ingredients: self-gravity, rotation, and a prescribed viscosity that enables the disk to accrete. We find that a super-Keplerian region can indeed exist when the viscosity is relatively large but, unlike the classic picture of centrifugal barrier, the infalling envelope material is not decelerated solely by the centrifugal force. The region has more specific angular momentum than its surrounding envelope material, which points to an origin in outward angular momentum transport in the disk (subject to the constraint of disk expansion by the infalling envelope), rather than the spin-up of the envelope material envisioned in the classic picture as it falls closer to the center in order to conserve angular momentum. For smaller viscosities, the super-Keplerian rotation is weaker or non-existing. We conclude that, despite the existence of super-Keplerian rotation in some parameter regime, the classic picture of centrifugal barrier is not supported by our simulations. △ Less

Submitted 7 July, 2022; originally announced July 2022.

Precision Møller Polarimetry for PREX and CREX

Authors: D. E. King, D. C. Jones, C. Gal, D. Gaskell, W. Henry, A. D. Kaplan, J. Napolitano, S. Park, K. D. Paschke, R. Pomatsalyuk, P. A. Souder

Abstract: The PREX-2 and CREX experiments in Hall A at Jefferson Lab are precision measurements of parity violating elastic electron scattering from complex nuclei. One requirement was that the incident electron beam polarization, typically $\approx$90\%, be known with 1\% precision. We commissioned and operated a Møller polarimeter on the beam line that exceeds this requirement, achieving a precision of 0.… ▽ More The PREX-2 and CREX experiments in Hall A at Jefferson Lab are precision measurements of parity violating elastic electron scattering from complex nuclei. One requirement was that the incident electron beam polarization, typically $\approx$90\%, be known with 1\% precision. We commissioned and operated a Møller polarimeter on the beam line that exceeds this requirement, achieving a precision of 0.89\% for PREX-2, and 0.85\% for CREX. The uncertainty is purely systematic, accumulated from several different sources, but dominated by our knowledge of the target polarization. Our analysis also demonstrates the need for accurate atomic wave functions in order to correct for the Levchuk Effect. We describe the details of the polarimeter operation and analysis, as well as (for CREX) a comparison to results from a different polarimeter based on Compton scattering. △ Less

Submitted 5 July, 2022; originally announced July 2022.

Precision Determination of the Neutral Weak Form Factor of $^{48}$Ca

Authors: D. Adhikari, H. Albataineh, D. Androic, K. A. Aniol, D. S. Armstrong, T. Averett, C. Ayerbe Gayoso, S. K. Barcus, V. Bellini, R. S. Beminiwattha, J. F. Benesch, H. Bhatt, D. Bhatta Pathak, D. Bhetuwal, B. Blaikie, J. Boyd, Q. Campagna, A. Camsonne, G. D. Cates, Y. Chen, C. Clarke, J. C. Cornejo, S. Covrig Dusa, M. M. Dalton, P. Datta , et al. (77 additional authors not shown)

Abstract: We report a precise measurement of the parity-violating asymmetry $A_{\rm PV}$ in the elastic scattering of longitudinally polarized electrons from $^{48}{\rm Ca}$. We measure $A_{\rm PV} =2668\pm 106\ {\rm (stat)}\pm 40\ {\rm (syst)}$ parts per billion, leading to an extraction of the neutral weak form factor $F_{\rm W} (q=0.8733$ fm… ▽ More We report a precise measurement of the parity-violating asymmetry $A_{\rm PV}$ in the elastic scattering of longitudinally polarized electrons from $^{48}{\rm Ca}$. We measure $A_{\rm PV} =2668\pm 106\ {\rm (stat)}\pm 40\ {\rm (syst)}$ parts per billion, leading to an extraction of the neutral weak form factor $F_{\rm W} (q=0.8733$ fm$^{-1}) = 0.1304 \pm 0.0052 \ {\rm (stat)}\pm 0.0020\ {\rm (syst)}$ and the charge minus the weak form factor $F_{\rm ch} - F_{\rm W} = 0.0277\pm 0.0055$. The resulting neutron skin thickness $R_n-R_p=0.121 \pm 0.026\ {\rm (exp)} \pm 0.024\ {\rm (model)}$~fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter. △ Less

Submitted 16 June, 2022; v1 submitted 23 May, 2022; originally announced May 2022.

Comments: 8 pages, 5 figures Replace 6-16-22: included ancillary files, corrected errors in references, author affiliations. Small text changes for clarity

Origin of spin reorientation and intrinsic anomalous Hall effect in the kagome ferrimagnet TbMn6Sn6

Authors: D. Connor Jones, Suvadip Das, Hari Bhandari, Xiaoxiong Liu, Peter Siegfried, Madhav P. Ghimire, Stepan S. Tsirkin, I. I. Mazin, Nirmal J. Ghimire

Abstract: TbMn$_6$Sn$_6$ has attracted a lot of recent interest for a variety of reasons, most importantly, because of the hypothesis that it may support quantum-limit Chern topological magnetism, derived from the kagome geometry. Besides, TbMn$_6$Sn$_6$ features a highly unusual magnetic reorientation transition about 100 K below the Curie point, whereby all spins in the system, remaining collinear, rotate… ▽ More TbMn$_6$Sn$_6$ has attracted a lot of recent interest for a variety of reasons, most importantly, because of the hypothesis that it may support quantum-limit Chern topological magnetism, derived from the kagome geometry. Besides, TbMn$_6$Sn$_6$ features a highly unusual magnetic reorientation transition about 100 K below the Curie point, whereby all spins in the system, remaining collinear, rotate by 90$^\circ$. In this work, we address both issues combining experiment, mean-field theory and first-principle calculations. Both magnetic reorientation and the unusual temperature dependence of the anomalous Hall conductivity (AHC) find quantitative explanation in the fact that Mn and Tb, by virtue of the Mermin-Wagner theorem, have very different spin dynamics, with Tb spins experiencing much more rapid fluctuation. We were able to cleanly extract the intrinsic AHC from our experiment, and calculated the same microscopically, with good semiquantitative agreement. We have identified the points in the band structure responsible for the AHC and showed that they are not the kagome-derived Dirac points at the K-corner of the Brillouin zone, as conjectured previously. △ Less

Submitted 28 September, 2024; v1 submitted 31 March, 2022; originally announced March 2022.

Journal ref: Physical Review B 110, 115134 (2024)

Accurate Determination of the Electron Spin Polarization In Magnetized Iron and Nickel Foils for Møller Polarimetry

Authors: D. C. Jones, J. Napolitano, P. A. Souder, D. E. King, W. Henry, D. Gaskell, K. Paschke

Abstract: The Møller polarimeter in Hall A at Jefferson Lab in Newport News, VA, has provided reliable measurements of electron beam polarization for the past two decades reaching the typically required $\pm$1\% level of absolute uncertainty. However, the upcoming proposed experimental program including MOLLER and SoLID have stringent requirements on beam polarimetry precision at the level of 0.4\% \cite{MO… ▽ More The Møller polarimeter in Hall A at Jefferson Lab in Newport News, VA, has provided reliable measurements of electron beam polarization for the past two decades reaching the typically required $\pm$1\% level of absolute uncertainty. However, the upcoming proposed experimental program including MOLLER and SoLID have stringent requirements on beam polarimetry precision at the level of 0.4\% \cite{MOLLER2014, SoLID2019}, requiring a systematic re-examination of all the contributing uncertainties. Møller polarimetry uses the double polarized scattering asymmetry of a polarized electron beam on a target with polarized atomic electrons. The target is a ferromagnetic material magnetized to align the spins in a given direction. In Hall A, the target is a pure iron foil aligned perpendicular to the beam and magnetized out of plane parallel or antiparallel to the beam direction. The acceptance of the detector is engineered to collect scattered electrons close to 90$^{\circ}$ in the center of mass frame where the analyzing power is a maximum (-7/9). One of the leading systematic errors comes from determination of the target foil polarization. Polarization of a magnetically saturated target foil requires knowledge of both the saturation magnetization and $g^\prime$, the electron $g$-factor which includes components from both spin and orbital angular momentum from which the spin fraction of magnetization is determined. This paper utilizes the existing world data to provide a best estimate for target polarization for both nickel and iron foils including uncertainties in magnetization, high-field and temperature dependence, and fractional contribution to magnetization from orbital effects. We determine the foil electron spin polarization at 294~K to be 0.08020$\pm$0.00018 (@4~T applied field) for iron and 0.018845$\pm0.000053$ (@2~T applied field) for nickel. △ Less

Submitted 1 July, 2022; v1 submitted 21 March, 2022; originally announced March 2022.

Physics Opportunities with PROSPECT-II

Authors: M. Andriamirado, A. B. Balantekin, C. D. Bass, D. E. Bergeron, E. Bernard, N. S. Bowden, C. D. Bryan, R. Carr, T. Classen, A. J. Conant, G. Deichert, A. Delgado, M. V. Diwan, M. J. Dolinski, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribari, C. E. Gilbert, S. Gokhale, C. Grant, S. Hans, A. B. Hansell, K. M. Heeger, B. Heffron , et al. (39 additional authors not shown)

Abstract: The PROSPECT experiment has substantially addressed the original 'Reactor Antineutrino Anomaly' by performing a high-resolution spectrum measurement from an enriched compact reactor core and a reactor model-independent sterile neutrino oscillation search based on the unique spectral distortions the existence of eV$^2$-scale sterile neutrinos would impart. But as the field has evolved, the current… ▽ More The PROSPECT experiment has substantially addressed the original 'Reactor Antineutrino Anomaly' by performing a high-resolution spectrum measurement from an enriched compact reactor core and a reactor model-independent sterile neutrino oscillation search based on the unique spectral distortions the existence of eV$^2$-scale sterile neutrinos would impart. But as the field has evolved, the current short-baseline (SBL) landscape supports many complex phenomenological interpretations, establishing a need for complementary experimental approaches to resolve the situation. While the global suite of SBL reactor experiments, including PROSPECT, have probed much of the sterile neutrino parameter space, there remains a large region above 1 eV$^2$ that remains unaddressed. Recent results from BEST confirm the Gallium Anomaly, increasing its significance to $\sim 5σ$, with sterile neutrinos providing a possible explanation of this anomaly. Separately, the MicroBooNE exclusion of electron-like signatures causing the MiniBooNE low-energy excess does not eliminate the possibility of sterile neutrinos as an explanation. Focusing specifically on the future use of reactors as a neutrino source for beyond-the-standard-model physics and applications, higher-precision spectral measurements still have a role to play. These recent results have created a confusing landscape which requires new data to disentangle the seemingly contradictory measurements. To directly probe $\overlineν_{e}$ disappearance from high $Δm^2$ sterile neutrinos, the PROSPECT collaboration proposes to build an upgraded and improved detector, PROSPECT-II. It features an evolutionary detector design which can be constructed and deployed within one year and have impactful physics with as little as one calendar year of data. △ Less

Submitted 14 July, 2022; v1 submitted 24 February, 2022; originally announced February 2022.

Comments: contribution to Snowmass 2021

First Determination of the 27Al Neutron Distribution Radius from a Parity-Violating Electron Scattering Measurement

Authors: QWeak Collaboration, D. Androic, D. S. Armstrong, K. Bartlett, R. S. Beminiwattha, J. Benesch, F. Benmokhtar, J. Birchall, R. D. Carlini, J. C. Cornejo, S. Covrig Dusa, M. M. Dalton, C. A. Davis, W. Deconinck, J. F. Dowd, J. A. Dunne, D. Dutta, W. S. Duvall, M. Elaasar, W. R. Falk, J. M. Finn, T. Forest, C. Gal, D. Gaskell, M. T. W. Gericke , et al. (69 additional authors not shown)

Abstract: We report the first measurement of the parity-violating elastic electron scattering asymmetry on 27Al. The 27Al elastic asymmetry is A_PV = 2.16 +- 0.11 (stat) +- 0.16 (syst) ppm, and was measured at <Q^2> =0.02357 +- 0.0001 GeV^2, <theta_lab> = 7.61 +- 0.02 degrees, and <E_lab> = 1.157 GeV with the Qweak apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sop… ▽ More We report the first measurement of the parity-violating elastic electron scattering asymmetry on 27Al. The 27Al elastic asymmetry is A_PV = 2.16 +- 0.11 (stat) +- 0.16 (syst) ppm, and was measured at <Q^2> =0.02357 +- 0.0001 GeV^2, <theta_lab> = 7.61 +- 0.02 degrees, and <E_lab> = 1.157 GeV with the Qweak apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the 27Al neutron radius R_n = 2.89 +- 0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_n-R_p = -0.04 +- 0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the 27Al weak radius R_w = 3.00 +- 0.15 fm, and the weak skin thickness R_wk - R_ch = -0.04 +- 0.15 fm. The weak form factor at this Q^2 is F_wk = 0.39 +- 0.04. △ Less

Submitted 11 March, 2022; v1 submitted 31 December, 2021; originally announced December 2021.

Comments: Revised version after referee's comments and suggestions. Some improvements and clarification to the text, no changes to the figures, tables, results or conclusions. 7 pages, 3 figures, 3 tables

Journal ref: Phys. Rev. Lett. 128, 13250 (2022)

New Measurements of the Beam-Normal Single Spin Asymmetry in Elastic Electron Scattering Over a Range of Spin-0 Nuclei

Authors: PREX, CREX Collaborations, :, D. Adhikari, H. Albataineh, D. Androic, K. Aniol, D. S. Armstrong, T. Averett, C. Ayerbe Gayoso, S. Barcus, V. Bellini, R. S. Beminiwattha, J. F. Benesch, H. Bhatt, D. Bhatta Pathak, D. Bhetuwal, B. Blaikie, J. Boyd, Q. Campagna, A. Camsonne, G. D. Cates, Y. Chen, C. Clarke, J. C. Cornejo , et al. (82 additional authors not shown)

Abstract: We report precision determinations of the beam normal single spin asymmetries ($A_n$) in the elastic scattering of 0.95 and 2.18~GeV electrons off $^{12}$C, $^{40}$Ca, $^{48}$Ca, and $^{208}$Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of $A_n$ for $^{40}$Ca and $^{48}$Ca are found to be similar to that of $^{12}$C, consiste… ▽ More We report precision determinations of the beam normal single spin asymmetries ($A_n$) in the elastic scattering of 0.95 and 2.18~GeV electrons off $^{12}$C, $^{40}$Ca, $^{48}$Ca, and $^{208}$Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of $A_n$ for $^{40}$Ca and $^{48}$Ca are found to be similar to that of $^{12}$C, consistent with expectations thus demonstrating the validity of theoretical calculations for nuclei with Z~$\leq20$. We also report $A_n$ for $^{208}$Pb at two new momentum transfers (Q$^2$) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the $Z\leq 20$ nuclei. These data confirm our basic understanding of the underlying dynamics that govern $A_n$ for nuclei containing $\lesssim 50$ nucleons, but point to the need for further investigation to understand the unusual $A_n$ behaviour discovered for scattering off $^{208}$Pb. △ Less

Submitted 9 August, 2022; v1 submitted 7 November, 2021; originally announced November 2021.

Comments: 7 pages, 2 figures

Journal ref: Phys.Rev.Lett. 128 (2022) 14, 142501

PROSPECT-II Physics Opportunities

Authors: M. Andriamirado, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, N. S. Bowden, C. D. Bryan, R. Carr, T. Classen, A. J. Conant, G. Deichert, A. Delgado, M. V. Diwan, M. J. Dolinski, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribari, C. E. Gilbert, C. Grant, S. Hans, A. B. Hansell, K. M. Heeger, B. Heffron, D. E. Jaffe , et al. (37 additional authors not shown)

Abstract: The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, has made world-leading measurements of reactor antineutrinos at short baselines. In its first phase, conducted at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, PROSPECT produced some of the strongest limits on eV-scale sterile neutrinos, made a precision measurement of the reactor antineutrino spectrum fr… ▽ More The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, has made world-leading measurements of reactor antineutrinos at short baselines. In its first phase, conducted at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, PROSPECT produced some of the strongest limits on eV-scale sterile neutrinos, made a precision measurement of the reactor antineutrino spectrum from $^{235}$U, and demonstrated the observation of reactor antineutrinos in an aboveground detector with good energy resolution and well-controlled backgrounds. The PROSPECT collaboration is now preparing an upgraded detector, PROSPECT-II, to probe yet unexplored parameter space for sterile neutrinos and contribute to a full resolution of the Reactor Antineutrino Anomaly, a longstanding puzzle in neutrino physics. By pressing forward on the world's most precise measurement of the $^{235}$U antineutrino spectrum and measuring the absolute flux of antineutrinos from $^{235}$U, PROSPECT-II will sharpen a tool with potential value for basic neutrino science, nuclear data validation, and nuclear security applications. Following a two-year deployment at HFIR, an additional PROSPECT-II deployment at a low enriched uranium reactor could make complementary measurements of the neutrino yield from other fission isotopes. PROSPECT-II provides a unique opportunity to continue the study of reactor antineutrinos at short baselines, taking advantage of demonstrated elements of the original PROSPECT design and close access to a highly enriched uranium reactor core. △ Less

Submitted 3 September, 2022; v1 submitted 8 July, 2021; originally announced July 2021.

Journal ref: J. Phys. G: Nucl. Part. Phys. 49, 070501 (2022)

Joint Measurement of the $^{235}$U Antineutrino Spectrum by Prospect and Stereo

Authors: H. Almazán, M. Andriamirado, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, L. Bernard, A. Blanchet, A. Bonhomme, N. S. Bowden, C. D. Bryan, C. Buck, T. Classen, A. J. Conant, G. Deichert, P. del Amo Sanchez, A. Delgado, M. V. Diwan, M. J. Dolinski, I. El Atmani, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribarri, C. E. Gilbert , et al. (60 additional authors not shown)

Abstract: The PROSPECT and STEREO collaborations present a combined measurement of the pure $^{235}$U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral measurements of the two highest precision experiments at research reactors are found to be compatible with $χ^2/\mathrm{ndf} = 24.1/21$, allowing a joint unfolding of the prompt energy measurements into anti… ▽ More The PROSPECT and STEREO collaborations present a combined measurement of the pure $^{235}$U antineutrino spectrum, without site specific corrections or detector-dependent effects. The spectral measurements of the two highest precision experiments at research reactors are found to be compatible with $χ^2/\mathrm{ndf} = 24.1/21$, allowing a joint unfolding of the prompt energy measurements into antineutrino energy. This $\barν_e$ energy spectrum is provided to the community, and an excess of events relative to the Huber model is found in the 5-6 MeV region. When a Gaussian bump is fitted to the excess, the data-model $χ^2$ value is improved, corresponding to a $2.4σ$ significance. △ Less

Submitted 7 July, 2021; originally announced July 2021.

Joint Determination of Reactor Antineutrino Spectra from $^{235}$U and $^{239}$Pu Fission by Daya Bay and PROSPECT

Authors: Daya Bay Collaboration, PROSPECT Collaboration, F. P. An, M. Andriamirado, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, M. Bishai, S. Blyth, N. S. Bowden, C. D. Bryan, G. F. Cao, J. Cao, J. F. Chang, Y. Chang, H. S. Chen, S. M. Chen, Y. Chen, Y. X. Chen, J. Cheng, Z. K. Cheng, J. J. Cherwinka, M. C. Chu , et al. (217 additional authors not shown)

Abstract: A joint determination of the reactor antineutrino spectra resulting from the fission of $^{235}$U and $^{239}$Pu has been carried out by the Daya Bay and PROSPECT collaborations. This Letter reports the level of consistency of $^{235}$U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The c… ▽ More A joint determination of the reactor antineutrino spectra resulting from the fission of $^{235}$U and $^{239}$Pu has been carried out by the Daya Bay and PROSPECT collaborations. This Letter reports the level of consistency of $^{235}$U spectrum measurements from the two experiments and presents new results from a joint analysis of both data sets. The measurements are found to be consistent. The combined analysis reduces the degeneracy between the dominant $^{235}$U and $^{239}$Pu isotopes and improves the uncertainty of the $^{235}$U spectral shape to about 3\%. The ${}^{235}$U and $^{239}$Pu antineutrino energy spectra are unfolded from the jointly deconvolved reactor spectra using the Wiener-SVD unfolding method, providing a data-based reference for other reactor antineutrino experiments and other applications. This is the first measurement of the $^{235}$U and $^{239}$Pu spectra based on the combination of experiments at low- and highly enriched uranium reactors. △ Less

Submitted 22 February, 2022; v1 submitted 23 June, 2021; originally announced June 2021.

Comments: 8 pages, 5 figures, Supplementary Material Included

Journal ref: Physical Review Letters 128, 081801 (2022)

Bridging observation, theory and numerical simulation of the ocean using Machine Learning

Authors: Maike Sonnewald, Redouane Lguensat, Daniel C. Jones, Peter D. Dueben, Julien Brajard, Venkatramani Balaji

Abstract: Progress within physical oceanography has been concurrent with the increasing sophistication of tools available for its study. The incorporation of machine learning (ML) techniques offers exciting possibilities for advancing the capacity and speed of established methods and also for making substantial and serendipitous discoveries. Beyond vast amounts of complex data ubiquitous in many modern scie… ▽ More Progress within physical oceanography has been concurrent with the increasing sophistication of tools available for its study. The incorporation of machine learning (ML) techniques offers exciting possibilities for advancing the capacity and speed of established methods and also for making substantial and serendipitous discoveries. Beyond vast amounts of complex data ubiquitous in many modern scientific fields, the study of the ocean poses a combination of unique challenges that ML can help address. The observational data available is largely spatially sparse, limited to the surface, and with few time series spanning more than a handful of decades. Important timescales span seconds to millennia, with strong scale interactions and numerical modelling efforts complicated by details such as coastlines. This review covers the current scientific insight offered by applying ML and points to where there is imminent potential. We cover the main three branches of the field: observations, theory, and numerical modelling. Highlighting both challenges and opportunities, we discuss both the historical context and salient ML tools. We focus on the use of ML in situ sampling and satellite observations, and the extent to which ML applications can advance theoretical oceanographic exploration, as well as aid numerical simulations. Applications that are also covered include model error and bias correction and current and potential use within data assimilation. While not without risk, there is great interest in the potential benefits of oceanographic ML applications; this review caters to this interest within the research community. △ Less

Submitted 11 June, 2021; v1 submitted 26 April, 2021; originally announced April 2021.

Comments: Topical review submitted to Environmental Research Letters

Limits on Sub-GeV Dark Matter from the PROSPECT Reactor Antineutrino Experiment

Authors: M. Andriamirado, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, N. S. Bowden, C. D. Bryan, T. Classen, A. J. Conant, G. Deichert, M. V. Diwan, M. J. Dolinski, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribarri, C. E. Gilbert, S. Hans, A. B. Hansell, K. M. Heeger, B. Heffron, D. E. Jaffe, S. Jayakumar, X. Ji, D. C. Jones , et al. (33 additional authors not shown)

Abstract: If dark matter has mass lower than around 1 GeV, it will not impart enough energy to cause detectable nuclear recoils in many direct-detection experiments. However, if dark matter is upscattered to high energy by collisions with cosmic rays, it may be detectable in both direct-detection experiments and neutrino experiments. We report the results of a dedicated search for boosted dark matter upscat… ▽ More If dark matter has mass lower than around 1 GeV, it will not impart enough energy to cause detectable nuclear recoils in many direct-detection experiments. However, if dark matter is upscattered to high energy by collisions with cosmic rays, it may be detectable in both direct-detection experiments and neutrino experiments. We report the results of a dedicated search for boosted dark matter upscattered by cosmic rays using the PROSPECT reactor antineutrino experiment. We show that such a flux of upscattered dark matter would display characteristic diurnal sidereal modulation, and use this to set new experimental constraints on sub-GeV dark matter exhibiting large interaction cross-sections. △ Less

Submitted 21 July, 2021; v1 submitted 22 April, 2021; originally announced April 2021.

Comments: 11 pages, 8 figures

Journal ref: Phys. Rev. D 104, 012009 (2021)

Measurement of the Beam-Normal Single-Spin Asymmetry for Elastic Electron Scattering from $^{12}$C and $^{27}$Al

Authors: QWeak Collaboration, D. Androic, D. S. Armstrong, A. Asaturyan, K. Bartlett, R. S. Beminiwattha, J. Benesch, F. Benmokhtar, J. Birchall, R. D. Carlini, M. E. Christy, J. C. Cornejo, S. Covrig Dusa, M. M. Dalton, C. A. Davis, W. Deconinck, J. F. Dowd, J. A. Dunne, D. Dutta, W. S. Duvall, M. Elassar, W. R. Falk, J. M. Finn, T. Forest, C. Gal , et al. (60 additional authors not shown)

Abstract: We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of $B_n$ on $^{12}$C and provide a first measurement on $^{27}$Al. The experiment utilized the… ▽ More We report measurements of the parity-conserving beam-normal single-spin elastic scattering asymmetries $B_n$ on $^{12}$C and $^{27}$Al, obtained with an electron beam polarized transverse to its momentum direction. These measurements add an additional kinematic point to a series of previous measurements of $B_n$ on $^{12}$C and provide a first measurement on $^{27}$Al. The experiment utilized the Qweak apparatus at Jefferson Lab with a beam energy of 1.158 GeV. The average lab scattering angle for both targets was 7.7 degrees, and the average $Q^2$ for both targets was 0.02437 GeV$^2$ (Q=0.1561 GeV). The asymmetries are $B_n$ = -10.68 $\pm$ 0.90 stat) $\pm$ 0.57 (syst) ppm for $^{12}$C and $B_n$ = -12.16 $\pm$ 0.58 (stat) $\pm$ 0.62 (syst) ppm for $^{27}$Al. The results are consistent with theoretical predictions, and are compared to existing data. When scaled by Z/A, the Q-dependence of all the far-forward angle (theta < 10 degrees) data from $^{1}$H to $^{27}$Al can be described by the same slope out to $Q \approx 0.35$ GeV. Larger-angle data from other experiments in the same Q range are consistent with a slope about twice as steep. △ Less

Submitted 18 June, 2021; v1 submitted 17 March, 2021; originally announced March 2021.

Comments: Minor changes after refereeing; version as accepted for Physical Review C. Cosmetic changes to several figures, one author added. 22 pages, 8 figures

Journal ref: Phys. Rev. C 104, 014606 (2021)

Accurate Determination of the Neutron Skin Thickness of $^{208}$Pb through Parity-Violation in Electron Scattering

Authors: D. Adhikari, H. Albataineh, D. Androic, K. Aniol, D. S. Armstrong, T. Averett, S. Barcus, V. Bellini, R. S. Beminiwattha, J. F. Benesch, H. Bhatt, D. Bhatta Pathak, D. Bhetuwal, B. Blaikie, Q. Campagna, A. Camsonne, G. D. Cates, Y. Chen, C. Clarke, J. C. Cornejo, S. Covrig Dusa, P. Datta, A. Deshpande, D. Dutta, C. Feldman , et al. (76 additional authors not shown)

Abstract: We report a precision measurement of the parity-violating asymmetry $A_{PV}$ in the elastic scattering of longitudinally polarized electrons from $^{208}$Pb. We measure $A_{PV}=550\pm 16 {\rm (stat)}\pm 8\ {\rm (syst)}$ parts per billion, leading to an extraction of the neutral weak form factor $F_W(Q^2 = 0.00616\ {\rm GeV}^2) = 0.368 \pm 0.013$. Combined with our previous measurement, the extract… ▽ More We report a precision measurement of the parity-violating asymmetry $A_{PV}$ in the elastic scattering of longitudinally polarized electrons from $^{208}$Pb. We measure $A_{PV}=550\pm 16 {\rm (stat)}\pm 8\ {\rm (syst)}$ parts per billion, leading to an extraction of the neutral weak form factor $F_W(Q^2 = 0.00616\ {\rm GeV}^2) = 0.368 \pm 0.013$. Combined with our previous measurement, the extracted neutron skin thickness is $R_n-R_p=0.283 \pm 0.071$~fm. The result also yields the first significant direct measurement of the interior weak density of $^{208}$Pb: $ρ^0_W = -0.0796\pm0.0036\ {\rm (exp.)}\pm0.0013\ {\rm (theo.)}\ {\rm fm}^{-3}$ leading to the interior baryon density $ρ^0_b = 0.1480\pm0.0036\ {\rm (exp.)}\pm0.0013\ {\rm (theo.)}\ {\rm fm}^{-3}$. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars. △ Less

Submitted 26 April, 2021; v1 submitted 21 February, 2021; originally announced February 2021.

Journal ref: Phys. Rev. Lett. 126, 172502 (2021)

Novel magnetic states and nematic spin chirality in the kagome lattice metal YMn$_{6}$Sn$_{6}$

Authors: Nirmal J. Ghimire, Rebecca L. Dally, L. Poudel, D. C. Jones, D. Michel, N. Thapa Magar, M. Bleuel, Michael A. McGuire, J. S. Jiang, J. F. Mitchell, Jeffrey W. Lynn, I. I. Mazin

Abstract: Identification, understanding, and manipulation of novel magnetic textures is essential for the discovery of new quantum materials for future spin-based electronic devices. In particular, materials that manifest a large response to external stimuli such as a magnetic field are subject to intense investigation. Here, we study the kagome-net magnet YMn$_{6}$Sn$_{6}$ by magnetometry, transport, and n… ▽ More Identification, understanding, and manipulation of novel magnetic textures is essential for the discovery of new quantum materials for future spin-based electronic devices. In particular, materials that manifest a large response to external stimuli such as a magnetic field are subject to intense investigation. Here, we study the kagome-net magnet YMn$_{6}$Sn$_{6}$ by magnetometry, transport, and neutron diffraction measurements combined with first principles calculations. We identify a number of nontrivial magnetic phases, explain their microscopic nature, and demonstrate that one of them hosts a large topological Hall effect (THE). We propose a new nematic chirality mechanism, reminiscent of the nematicity in Fe-based superconductors, which leads to the THE at elevated temperatures. This interesting physics comes from parametrically frustrated interplanar exchange interactions that trigger strong magnetic fluctuations. Our results pave a path to new chiral spin textures, promising for novel spintronics. △ Less

Submitted 5 July, 2020; originally announced July 2020.

Journal ref: Science Advances 6, eabe2680 (2020)

Note on arXiv:2005.05301, 'Preparation of the Neutrino-4 experiment on search for sterile neutrino and the obtained results of measurements'

Authors: H. Almazán, M. Andriamirado, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, A. Bonhomme, N. S. Bowden, J. P. Brodsky, C. D. Bryan, C. Buck, T. Classen, A. J. Conant, G. Deichert, P. del Amo Sanchez, M. V. Diwan, M. J. Dolinski, I. El Atmani, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribarri, C. E. Gilbert, B. T. Hackett , et al. (57 additional authors not shown)

Abstract: We comment on the claimed observation [arXiv:arXiv:2005.05301] of sterile neutrino oscillations by the Neutrino-4 collaboration. Such a claim, which requires the existence of a new fundamental particle, demands a level of rigor commensurate with its impact. The burden lies with the Neutrino-4 collaboration to provide the information necessary to prove the validity of their claim to the community.… ▽ More We comment on the claimed observation [arXiv:arXiv:2005.05301] of sterile neutrino oscillations by the Neutrino-4 collaboration. Such a claim, which requires the existence of a new fundamental particle, demands a level of rigor commensurate with its impact. The burden lies with the Neutrino-4 collaboration to provide the information necessary to prove the validity of their claim to the community. In this note, we describe aspects of both the data and analysis method that might lead to an oscillation signature arising from a null experiment and describe additional information needed from the Neutrino-4 collaboration to support the oscillation claim. Additionally, as opposed to the assertion made by the Neutrino-4 collaboration, we also show that the method of 'coherent summation' using the $L/E$ parameter produces similar results to the methods used by the PROSPECT and the STEREO collaborations. △ Less

Submitted 23 June, 2020; originally announced June 2020.

Comments: 5 pages, 3 figures

Improved Short-Baseline Neutrino Oscillation Search and Energy Spectrum Measurement with the PROSPECT Experiment at HFIR

Authors: M. Andriamirado, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, N. S. Bowden, J. P. Brodsky, C. D. Bryan, T. Classen, A. J. Conant, G. Deichert, M. V. Diwan, M. J. Dolinski, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribarri, C. E. Gilbert, B. W. Goddard, B. T. Hackett, S. Hans, A. B. Hansell, K. M. Heeger, B. Heffron , et al. (39 additional authors not shown)

Abstract: We present a detailed report on sterile neutrino oscillation and U-235 antineutrino energy spectrum measurement results from the PROSPECT experiment at the highly enriched High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. In 96 calendar days of data taken at an average baseline distance of 7.9 m from the center of the 85 MW HFIR core, the PROSPECT detector has observed more than 5… ▽ More We present a detailed report on sterile neutrino oscillation and U-235 antineutrino energy spectrum measurement results from the PROSPECT experiment at the highly enriched High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. In 96 calendar days of data taken at an average baseline distance of 7.9 m from the center of the 85 MW HFIR core, the PROSPECT detector has observed more than 50,000 interactions of antineutrinos produced in beta decays of U-235 fission products. New limits on the oscillation of antineutrinos to light sterile neutrinos have been set by comparing the detected energy spectra of ten reactor-detector baselines between 6.7 and 9.2 meters. Measured differences in energy spectra between baselines show no statistically significant indication of antineutrinos to sterile neutrino oscillation and disfavor the Reactor Antineutrino Anomaly best-fit point at the 2.5$σ$ confidence level. The reported U-235 antineutrino energy spectrum measurement shows excellent agreement with energy spectrum models generated via conversion of the measured U-235 beta spectrum, with a $χ^2$/DOF of 31/31. PROSPECT is able to disfavor at 2.4$σ$ confidence level the hypothesis that U-235 antineutrinos are solely responsible for spectrum discrepancies between model and data obtained at commercial reactor cores. A data-model deviation in PROSPECT similar to that observed by commercial core experiments is preferred with respect to no observed deviation, at a 2.2$σ$ confidence level. △ Less

Submitted 1 July, 2020; v1 submitted 19 June, 2020; originally announced June 2020.

Comments: 42 pages, 52 Figures. Submitted to Phys. Rev. D. Supplementary Material Included

Journal ref: Phys. Rev. D 103, 032001 (2021)

Nonfuel Antineutrino Contributions in the High Flux Isotope Reactor

Authors: A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, N. S. Bowden, J. P. Brodsky, C. D. Bryan, T. Classen, A. J. Conant, G. Deichert, M. V. Diwan, M. J. Dolinski, A. Erickson, B. T. Foust, J. K. Gaison, A. Galindo-Uribarri, C. E. Gilbert, B. T. Hackett S. Hans, A. B. Hansell, K. M. Heeger, B. Heffron D. E. Jaffe, X. Ji, D. C. Jones, O. Kyzylova , et al. (31 additional authors not shown)

Abstract: Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of $\overlineν_{e}$ is important when making theoretical predictions. One source of $\overlineν_{e}$ that is often neglected arises from the irradiation of the nonfuel materials in reactors. The… ▽ More Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of $\overlineν_{e}$ is important when making theoretical predictions. One source of $\overlineν_{e}$ that is often neglected arises from the irradiation of the nonfuel materials in reactors. The $\overlineν_{e}$ rates and energies from these sources vary widely based on the reactor type, configuration, and sampling stage during the reactor cycle and have to be carefully considered for each experiment independently. In this article, we present a formalism for selecting the possible $\overlineν_{e}$ sources arising from the neutron captures on reactor and target materials. We apply this formalism to the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, the $\overlineν_{e}$ source for the the Precision Reactor Oscillation and Spectrum Measurement (PROSPECT) experiment. Overall, we observe that the nonfuel $\overlineν_{e}$ contributions from HFIR to PROSPECT amount to 1\% above the inverse beta decay threshold with a maximum contribution of 9\% in the 1.8--2.0~MeV range. Nonfuel contributions can be particularly high for research reactors like HFIR because of the choice of structural and reflector material in addition to the intentional irradiation of target material for isotope production. We show that typical commercial pressurized water reactors fueled with low-enriched uranium will have significantly smaller nonfuel $\overlineν_{e}$ contribution. △ Less

Submitted 31 March, 2020; v1 submitted 27 March, 2020; originally announced March 2020.

Journal ref: Phys. Rev. C 101, 054605 (2020)

The Radioactive Source Calibration System of the PROSPECT Reactor Antineutrino Detector

Authors: PROSPECT Collaboration, J. Ashenfelter, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, N. S. Bowden, J. P. Brodsky, C. D. Bryan, J. J. Cherwinka, T. Classen, A. J. Conant, D. Dean, G. Deichert, M. V. Diwan, M. J. Dolinski, A. Erickson, B. T. Foust, M. Febbraro, J. K. Gaison, A. Galindo-Uribarri, C. E. Gilbert, B. T. Hackett, S. Hans , et al. (40 additional authors not shown)

Abstract: The Precision Reactor Oscillation and Spectrum (PROSPECT) Experiment is a reactor neutrino experiment designed to search for sterile neutrinos with a mass on the order of 1 eV/c$^2$ and to measure the spectrum of electron antineutrinos from a highly-enriched $^{235}$U nuclear reactor. The PROSPECT detector consists of an 11 by 14 array of optical segments in $^{6}$Li-loaded liquid scintillator at… ▽ More The Precision Reactor Oscillation and Spectrum (PROSPECT) Experiment is a reactor neutrino experiment designed to search for sterile neutrinos with a mass on the order of 1 eV/c$^2$ and to measure the spectrum of electron antineutrinos from a highly-enriched $^{235}$U nuclear reactor. The PROSPECT detector consists of an 11 by 14 array of optical segments in $^{6}$Li-loaded liquid scintillator at the High Flux Isotope Reactor in Oak Ridge National Laboratory. Antineutrino events are identified via inverse beta decay and read out by photomultiplier tubes located at the ends of each segment. The detector response is characterized using a radioactive source calibration system. This paper describes the design, operation, and performance of the PROSPECT source calibration system. △ Less

Submitted 16 August, 2019; v1 submitted 17 June, 2019; originally announced June 2019.

Journal ref: Nucl. Instrum. Methods A, Vol. 944, 2019

A Low Mass Optical Grid for the PROSPECT Reactor Antineutrino Detector

Authors: PROSPECT Collaboration, J. Ashenfelter, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, N. S. Bowden, J. P. Brodsky, C. D. Bryan, J. J. Cherwinka, T. Classen, A. J. Conant, D. Davee, D. Dean, G. Deichert, A. E. Detweiler M. V. Diwan, M. J. Dolinski, A. Erickson, M. Febbraro, B. T. Foust, J. K. Gaison, A. Galindo-Uribarri, Y. Gebre, C. E. Gilbert , et al. (45 additional authors not shown)

Abstract: PROSPECT, the Precision Reactor Oscillation and SPECTrum experiment, is a short-baseline reactor antineutrino experiment designed to provide precision measurements of the $^{235}$U product $\overlineν_e$ spectrum of utilizing an optically segmented 4-ton liquid scintillator detector. PROSPECT's segmentation system, the optical grid, plays a central role in reconstructing the position and energy of… ▽ More PROSPECT, the Precision Reactor Oscillation and SPECTrum experiment, is a short-baseline reactor antineutrino experiment designed to provide precision measurements of the $^{235}$U product $\overlineν_e$ spectrum of utilizing an optically segmented 4-ton liquid scintillator detector. PROSPECT's segmentation system, the optical grid, plays a central role in reconstructing the position and energy of $\overlineν_e$ interactions in the detector. This paper is the technical reference for this PROSPECT subsystem, describing its design, fabrication, quality assurance, transportation and assembly in detail. In addition, the dimensional, optical and mechanical characterizations of optical grid components and the assembled PROSPECT target are also presented. The technical information and characterizations detailed here will inform geometry-related inputs for PROSPECT physics analysis, and can guide a variety of future particle detection development efforts, such as those using optically reflecting materials or filament-based 3D printing. △ Less

Submitted 9 April, 2019; v1 submitted 18 February, 2019; originally announced February 2019.

Comments: 31 pages, 28 figures

Lithium-loaded Liquid Scintillator Production for the PROSPECT experiment

Authors: PROSPECT Collaboration, J. Ashenfelter, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, L. J. Bignell, N. S. Bowden, J. P. Brodsky, C. D. Bryan, C. Camilo Reyes, S. Campos, J. J. Cherwinka, T. Classen, A. J. Conant, D. Davee, D. Dean, G. Deichert, R. Diaz Perez, M. V. Diwan, M. J. Dolinski, A. Erickson, M. Febbraro, B. T. Foust , et al. (45 additional authors not shown)

Abstract: This work reports the production and characterization of lithium-loaded liquid scintillator (LiLS) for the Precision Reactor Oscillation and Spectrum Experiment (PROSPECT). Fifty-nine 90 liter batches of LiLS (${}^6{\rm Li}$ mass fraction 0.082%$\pm$0.001%) were produced and samples from all batches were characterized by measuring their optical absorbance relative to air, light yield relative to a… ▽ More This work reports the production and characterization of lithium-loaded liquid scintillator (LiLS) for the Precision Reactor Oscillation and Spectrum Experiment (PROSPECT). Fifty-nine 90 liter batches of LiLS (${}^6{\rm Li}$ mass fraction 0.082%$\pm$0.001%) were produced and samples from all batches were characterized by measuring their optical absorbance relative to air, light yield relative to a pure liquid scintillator reference, and pulse shape discrimination capability. Fifty-seven batches passed the quality assurance criteria and were used for the PROSPECT experiment. △ Less

Submitted 27 March, 2019; v1 submitted 16 January, 2019; originally announced January 2019.

Comments: 16 pages, 15 figures

Journal ref: J. Ashenfelter et al 2019 JINST 14 P03026

Measurement of the Antineutrino Spectrum from $^{235}$U Fission at HFIR with PROSPECT

Authors: PROSPECT Collaboration, J. Ashenfelter, A. B. Balantekin, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, N. S. Bowden, J. P. Brodsky, C. D. Bryan, J. J. Cherwinka, T. Classen, A. J. Conant, A. A. Cox, D. Davee, D. Dean, G. Deichert, M. V. Diwan, M. J. Dolinski, A. Erickson, M. Febbraro, B. T. Foust, J. K. Gaison, A. Galindo-Uribarri, C. E. Gilbert , et al. (45 additional authors not shown)

Abstract: This Letter reports the first measurement of the $^{235}$U $\overline{ν_{e}}$ energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9m from the 85MW$_{\mathrm{th}}$ highly-enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678$\pm$304 (stat.) $\overline{ν_{e}}$-induced inverse beta decays… ▽ More This Letter reports the first measurement of the $^{235}$U $\overline{ν_{e}}$ energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9m from the 85MW$_{\mathrm{th}}$ highly-enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678$\pm$304 (stat.) $\overline{ν_{e}}$-induced inverse beta decays (IBD), the largest sample from HEU fission to date, 99% of which are attributed to $^{235}$U. Despite broad agreement, comparison of the Huber $^{235}$U model to the measured spectrum produces a $χ^2/ndf = 51.4/31$, driven primarily by deviations in two localized energy regions. The measured $^{235}$U spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the $\overline{ν_{e}}$ energy region of 5-7MeV. △ Less

Submitted 28 June, 2019; v1 submitted 27 December, 2018; originally announced December 2018.

Journal ref: Phys. Rev. Lett. 122, 251801 (2019)

The PROSPECT Reactor Antineutrino Experiment

Authors: PROSPECT Collaboration, J. Ashenfelter, A. B. Balantekin, C. Baldenegro, H. R. Band, C. D. Bass, D. E. Bergeron, D. Berish, L. J. Bignell, N. S. Bowden, J. Boyle, J. Bricco, J. P. Brodsky, C. D. Bryan, A. Bykadorova Telles, J. J. Cherwinka, T. Classen, K. Commeford, A. Conant, A. A. Cox, D. Davee, D. Dean, G. Deichert, M. V. Diwan, M. J. Dolinski , et al. (64 additional authors not shown)

Abstract: The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make both a precise measurement of the antineutrino spectrum from a highly-enriched uranium reactor and to probe eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long baselines. PROSPECT utilizes a segmented $^6$Li-doped liquid scintillator detector for both efficient detection of reacto… ▽ More The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, is designed to make both a precise measurement of the antineutrino spectrum from a highly-enriched uranium reactor and to probe eV-scale sterile neutrinos by searching for neutrino oscillations over meter-long baselines. PROSPECT utilizes a segmented $^6$Li-doped liquid scintillator detector for both efficient detection of reactor antineutrinos through the inverse beta decay reaction and excellent background discrimination. PROSPECT is a movable 4-ton antineutrino detector covering distances of 7m to 13m from the High Flux Isotope Reactor core. It will probe the best-fit point of the $\barν_e$ disappearance experiments at 4$σ$ in 1 year and the favored regions of the sterile neutrino parameter space at more than 3$σ$ in 3 years. PROSPECT will test the origin of spectral deviations observed in recent $θ_{13}$ experiments, search for sterile neutrinos, and address the hypothesis of sterile neutrinos as an explanation of the reactor anomaly. This paper describes the design, construction, and commissioning of PROSPECT and reports first data characterizing the performance of the PROSPECT antineutrino detector. △ Less

Submitted 21 August, 2019; v1 submitted 31 July, 2018; originally announced August 2018.

Comments: 30 pages, 33 figures; updated with journal revision and reference

Journal ref: Nucl.Instrum.Meth. A922 (2019) 287-309

Compression of next-generation sequencing reads aided by highly efficient de novo assembly

Authors: Daniel C. Jones, Walter L. Ruzzo, Xinxia Peng, Michael G. Katze

Abstract: We present Quip, a lossless compression algorithm for next-generation sequencing data in the FASTQ and SAM/BAM formats. In addition to implementing reference-based compression, we have developed, to our knowledge, the first assembly-based compressor, using a novel de novo assembly algorithm. A probabilistic data structure is used to dramatically reduce the memory required by traditional de Bruijn… ▽ More We present Quip, a lossless compression algorithm for next-generation sequencing data in the FASTQ and SAM/BAM formats. In addition to implementing reference-based compression, we have developed, to our knowledge, the first assembly-based compressor, using a novel de novo assembly algorithm. A probabilistic data structure is used to dramatically reduce the memory required by traditional de Bruijn graph assemblers, allowing millions of reads to be assembled very efficiently. Read sequences are then stored as positions within the assembled contigs. This is combined with statistical compression of read identifiers, quality scores, alignment information, and sequences, effectively collapsing very large datasets to less than 15% of their original size with no loss of information. Availability: Quip is freely available under the BSD license from http://cs.washington.edu/homes/dcjones/quip. △ Less

Submitted 10 July, 2012; originally announced July 2012.