Thu·Feb 17, 2022Thursday·February 17, 2022

1. 01*

   Nuclear Data to Reduce Uncertainties in Reactor Antineutrino Measurements: Summary Report of the Workshop on Nuclear Data for Reactor Antineutrino Measurements (WoNDRAM)

   Catherine Romano · Nathaniel Bowden🇺🇸 · Andrew Conant🇺🇸 · Bethany Goldblum🇺🇸 · Patrick Huber🇺🇸 · Jonathan Link🇺🇸 · Bryce Littlejohn🇺🇸 · Pieter Mumm · Juan Pedro Ochoa-Ricoux🇺🇸 · Shikha Prasad🇺🇸 · Catherine Riddle🇺🇸 · Alejandro Sonzogni · William Wieselquist

   The large quantities of antineutrinos produced through the decay of fission fragments in nuclear reactors provide an opportunity to study the properties of these particles and investigate their use in reactor monitoring. The reactor antineutrino spectra are measured using specialized, large area detectors that detect antineutrinos through inverse beta decay, electron elastic scattering, or coherent elastic neutrino nucleus scattering; although, inverse beta decay is the only demonstrated method so far. Reactor monitoring takes advantage of the differences in the antineutrino yield and spectra resulting from uranium and plutonium fission providing an opportunity to estimate the fissile material composition in the reactor. Recent experiments reveal a deviation between the measured and calculated antineutrino flux and spectra indicating either the existence of yet undiscovered neutrino physics, uncertainties in the reactor source term calculation, incorrect nuclear data, or a combination of all three. To address the nuclear data that impact the antineutrino spectrum calculations and measurements, an international group of over 180 experts in antineutrino physics, reactor analysis, detector development, and nuclear data came together during the Workshop on Nuclear Data for Reactor Antineutrino Measurements (WoNDRAM) to discuss nuclear data needs and achieve concordance on a set of recommended priorities for nuclear data improvements. Three topical sessions provided a forum to gain consensus amongst the participants on the most important data improvements to address two goals: 1) understand the reactor anomaly and 2) improve the ability to monitor reactors using antineutrinos. This report summarizes the outcomes of the workshop discussions and the recommendations for nuclear data efforts that reduce reactor antineutrino measurement uncertainties.

   nucl-exphysics.ins-det4 citations
2. 02*

   Evaluation of a Positron-Emission-Tomography-based SiPM readout for Compact Segmented Neutron Imagers

   Viacheslav A. Li🇺🇸 · Felicia Sutanto🇺🇸 · Timothy M. Classen🇺🇸 · Steven A. Dazeley🇺🇸 · Igor Jovanovic🇺🇸 · Tingshiuan C. Wu🇺🇸

   Gamma-ray emission from special nuclear material (SNM) is relatively easy to shield from detection using modest amounts of high-Z material. In contrast, fast-neutrons are much more penetrating and can escape relatively thick high-Z shielding without losing significant energy. Furthermore, fast neutrons provide a clear and unambiguous signature of the presence of SNM with few competing natural background sources. The challenge of detecting fast neutrons is twofold. First, the neutron flux from SNM are only a fraction of the corresponding gamma-ray flux. Second, fast neutrons can be difficult to differentiate from gamma rays. The ability to discriminate gamma rays from neutrons combined with neutron imaging can yield large benefit to isolate the localized SNM neutron source from background. With the recent developments of pulse-shape-sensitive plastic scintillators that offer excellent gamma-ray/neutron discrimination, and arrays of silicon photomultipliers combined with highly scalable and fast positron-emission-tomography (PET) multi-channel readout systems, field-deployable neutron imagers suitable for SNM detection might now be within reach. In this paper, we present a characterization of the performance of a recently available commercial PET-scanner readout, including its sensitivity to pulse-shape differences between fast neutrons and gamma rays, energy and timing resolution, as well as linearity and dynamic range. We find that, while the pulse-shape discrimination is achievable with stilbene, further improvement of the readout is required to achieve it with the best available plastic scintillators. The time and energy resolution appear to be adequate for neutron imaging in some circumstances.

   ↳ physics.ins-dethep-exnucl-exphysics.med-phNucl.Instrum.Meth.A(2023)·2 citations
3. 03*

   Characterization of Multianode Photomultiplier Tubes for use in the CLAS12 RICH Detector

   Pavel Degtiarenko (1)🇺🇸 · Andrey Kim (2)🇺🇸 · Valery Kubarovsky (1)🇺🇸 · Ben Raydo (1)🇺🇸 · Andrew Smith (3)🇺🇸 · Fatiha Benmokhtar (4) ((1) Thomas Jefferson National Accelerator Facility, (2) University of Connecticut, (3) Duke University, (4) Duquesne University)🇺🇸

   We present results of the detailed study of several hundred Hamamatsu H12700 Multianode Photomultiplier Tubes (MaPMTs), characterizing their response to the Cherenkov light photons in the second Ring Imaging Cherenkov detector, a part of the CLAS12 upgrade at Jefferson Lab. The total number of pixels studied was 25536. The single photoelectron spectra were measured for each pixel at different high voltages and light intensities of the laser test setup. Using the same dedicated front-end electronics as in the first RICH detector, the setup allowed us to characterize each pixel's properties such as gain, quantum efficiency, signal crosstalk between neighboring pixels, and determine the signal threshold values to optimize their efficiency to detect Cherenkov photons. A recently published state-of-the-art mathematical model, describing photon detector response functions measured in low light conditions, was extended to include the description of the crosstalk contributions to the spectra. The database of extracted parameters will be used for the final selection of the MaPMTs, their arrangement in the new RICH detector, and the optimization of the operational settings of the front-end electronics. The results show that the characteristics of the H12700 MaPMTs satisfy our requirements for the position-sensitive single photoelectron detectors.

   ↳ physics.ins-dethep-exnucl-exNucl.Instrum.Meth.A(2022)·1 citation
4. 04*

   Elastic pion-proton and pion-pion scattering at high energies in holographic QCD

   Zhibo Liu🇨🇳 · Wei Xie🇨🇳 · Fei Sun🇨🇳 · Shuang Li🇨🇳 · Akira Watanabe🇨🇳

   The total and differential cross sections of high energy pion-proton and pion-pion scattering are investigated in a holographic QCD model, focusing on the Regge regime in which the Pomeron exchange gives the dominant contribution to those cross sections. The Pomeron is described by the Reggeized spin-2 particle propagator, and the hadron-Pomeron couplings are given by gravitational form factors of the hadrons, which are obtained from the bottom-up AdS/QCD models. Since the parameters, which characterize the Pomeron trajectory, have been determined in a preceding study of the proton-proton scattering, the pion-proton cross sections can be expressed with a single adjustable parameter. Once this parameter is determined by the experimental data of the pion-proton total cross section, its differential cross section and the pion-pion cross sections can be calculated without any additional parameter. Although the currently available data are limited, it is found that our calculation is consistent with those. Our predictions are explicitly shown, and the present model can be tested at the future experimental facilities.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2022)·13 citations
5. 05*

   1-jettiness with jet axis at $O({\alpha }_s)$ in jeep inelastic scattering

   Zexuan Chu🇨🇳 · Yunlu Wang🇨🇳 · June-Haak Ee🇨🇳 · Jinhui Chen🇨🇳 · Daekyoung Kang🇨🇳

   We present $O({\alpha }_s)$ analytic predictions for event shape 1-jettiness ${\tau }_1$ distribution aiming measurements in deep inelastic scattering process at future Electron Ion Colliders. The result depends on conventional variables $x$ and $Q$ as well as on ${\tau }_1$ and is relatively compact and easy to implement for numerical calculation. Three different choices of axis, with respect to which ${\tau }_1$ is measured are considered in the Breit frame. The first is the one optimally adjusted to minimize ${\tau }_1$ and the second and third are taken from anti-$k_T$ and Centauro jet algorithms defined with a jet radius parameter $R$, respectively. We find that the first and second give the same result at this order and are independent of $R$, while the third depends on the radius. This fixed-order result provides a nonsingular contribution to be combined with a singular log-resummed contribution to give the full spectrum in ${\tau }_1$ space and also shows how fixed-order and resummation regions change as a function of $x$ and $Q$.

   ↳ hep-phnucl-exnucl-thJHEP(2022)·10 citations
6. 06*

   Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at $\sqrt{s}=510$ GeV in $\vec{p}+\vec{p}$ Collisions

   PHENIX Collaboration: N.J. Abdulameer · U. Acharya · A. Adare · C. Aidala · N.N. Ajitanand · Y. Akiba · R. Akimoto · M. Alfred · N. Apadula · Y. Aramaki · H. Asano · E.T. Atomssa and 349 other authors

   We present measurements of the cross section and double-helicity asymmetry $A_{LL}$ of direct-photon production in $\vec{p}+\vec{p}$ collisions at $\sqrt{s}=510$ GeV. The measurements have been performed at midrapidity ($|\eta |<0.25$) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at $\sqrt{s}=510$ GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range $0.02<x<0.08$, with direct sensitivity to the sign of the gluon contribution.

   ↳ hep-exnucl-exPRL(2023)·21 citations
7. 07*

   Status and initial physics performance studies of the MPD experiment at NICA

   MPD Collaboration: V. Abgaryan · R. Acevedo Kado · S.V. Afanasyev · G.N. Agakishiev · E. Alpatov · G. Altsybeev · M. Alvarado Hernández · S.V. Andreeva · T.V. Andreeva · E.V. Andronov · N.V. Anfimov · A.A. Aparin and 466 other authors

   The Nuclotron-base Ion Collider fAcility (NICA) is under construction at the Joint Institute for Nuclear Research (JINR), with commissioning of the facility expected in late 2022. The Multi-Purpose Detector (MPD) has been designed to operate at NICA and its components are currently in production. The detector is expected to be ready for data taking with the first beams from NICA. This document provides an overview of the landscape of the investigation of the QCD phase diagram in the region of maximum baryonic density, where NICA and MPD will be able to provide significant and unique input. It also provides a detailed description of the MPD set-up, including its various subsystems as well as its support and computing infrastructures. Selected performance studies for particular physics measurements at MPD are presented and discussed in the context of existing data and theoretical expectations.

   ↳ physics.ins-dethep-exnucl-exnucl-thEPJA(2022)·126 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.