Wed·Dec 7, 2022Wednesday·December 7, 2022

1. 01*

   Model-independent determination of nuclear weak form factors and implications for Standard Model precision tests

   Chien-Yeah Seng🇺🇸

   We analyze the recoil corrections in superallowed beta decays of $T=1$, $J^P=0^{+}$ nuclei by fixing the mean square charge weak radius model-independently using the data of multiple charge radii across the nuclear isotriplet. By comparing to model estimations, we argue that the existing theory uncertainty in the statistical rate function $f$ might have been substantially underestimated. We discuss the implications of our proposed strategy for precision tests of Standard Model, including a potential alleviation of the first-row CKM unitarity deficit, and motivate new experiments for charge radii measurements.

   ↳ nucl-thhep-exhep-phnucl-exPRL(2023)·26 citations
2. 02*

   Liquid argon light collection and veto modeling in GERDA Phase II

   GERDA collaboration: M. Agostini · A. Alexander · G. R. Araujo · A. M. Bakalyarov · M. Balata · I. Barabanov · L. Baudis · C. Bauer · S. Belogurov · A. Bettini · L. Bezrukov · V. Biancacci and 106 other authors

   The ability to detect liquid argon scintillation light from within a densely packed high-purity germanium detector array allowed the GERDA experiment to reach an exceptionally low background rate in the search for neutrinoless double beta decay of ${}^{76}$Ge. Proper modeling of the light propagation throughout the experimental setup, from any origin in the liquid argon volume to its eventual detection by the novel light read-out system, provides insight into the rejection capability and is a necessary ingredient to obtain robust background predictions. In this paper, we present a model of the GERDA liquid argon veto, as obtained by Monte Carlo simulations and constrained by calibration data, and highlight its application for background decomposition.

   ↳ physics.ins-dethep-exnucl-exEPJC(2023)·16 citations
3. 03*

   Event-by-event investigation of the two-particle source function in $\sqrt{s_{{}_{\text{NN}}}}=2.76$ TeV PbPb collisions with EPOS

   Balázs Kórodi🇭🇺 · Dániel Kincses🇭🇺 · Máté Csanád🇭🇺

   The investigation of the two-particle source function in lead-lead collisions simulated by the EPOS model at a center of mass energy per nucleon pair of $\sqrt{s_{{}_{\text{NN}}}}=2.76$ TeV is presented. The two-particle source functions are reconstructed directly on an event-by-event basis for pions, kaons and protons separately, using the final stage of EPOS. A Lévy source shape is observed for all three particle species in the individual events, deviating significantly from a Gaussian shape. The source parameters are extracted as functions of collision centrality and pair average transverse mass ($m_{\text{T}}$). The Lévy exponent is found to be ordered accordingly to particle mass. The Lévy scale parameter is found to scale for all particle species with $m_{\text{T}}$ according to Gaussian hydrodynamical predictions; however, there is no $m_{\text{T}}$-scaling found across these species. In case of pions, the effects of the decay products and hadronic rescattering are also investigated. The Lévy exponent is decreased when decay products are also included in the analysis. Without hadronic rescattering and decay products, the source shape is close to a Gaussian.

   ↳ nucl-thhep-phnucl-exPLB(2023)·23 citations
4. 04*

   Impact of globally spin-aligned vector mesons on the search for the chiral magnetic effect in heavy-ion collisions

   Diyu Shen🇨🇳 · Jinhui Chen🇨🇳 · Aihong Tang🇺🇸 · Gang Wang🇺🇸

   In high-energy heavy-ion collisions, the chiral magnetic effect (CME) is predicted to arise from the interplay between the chirality imbalance of quarks in the nuclear medium and the intense magnetic field, and will cause a charge separation along the magnetic field direction. While the search for the CME is still ongoing in experiments at Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), the CME-sensitive observables need to be scrutinized to exclude the non-CME contributions. In this work, we examine the influence of globally spin-aligned $\rho$ mesons on the ${\gamma }_{112}$ correlator, the $R_{{\Psi }_2}(\Delta S)$ correlator, and the signed balance functions, via a toy model and a multiphase transport model (AMPT). The global spin alignment of vector mesons could originate from non-CME mechanisms in heavy-ion collisions, and is characterized by the 00-component of the spin density matrix, ${\rho }_{00}$. We find that the CME observables show similar dependence on ${\rho }_{00}$, and could receive a positive (negative) contribution from $\rho$-decay pions, if the ${\rho }_{00}$ of $\rho$ mesons is larger (smaller) than 1/3. Since pions are the most abundant particles in such collisions, the ${\rho }_{00}$ measurements for $\rho$ mesons become crucial to the interpretation of the CME data.

   ↳ nucl-thnucl-exPLB(2023)·17 citations
5. 05*

   Advances in the Large Area Picosecond Photo-Detector (LAPPD): 8" x 8" MCP-PMT with Capacitively Coupled Readout

   Shawn Shin🇲🇦 · Melvin Aviles🇲🇦 · Stephen Clarke🇲🇦 · Stefan Cwik🇲🇦 · Michael Foley🇲🇦 · Cole Hamel🇲🇦 · Alexey Lyashenko🇲🇦 · Derrick Mensah🇲🇦 · Michael Minot🇲🇦 · Mark Popecki🇲🇦 · Michael Stochaj🇲🇦

   We present advances made in the Large Area Picosecond Photodetector (LAPPD), an 8" $\times$ 8" microchannel plate photomultiplier tube (MCP-PMT), since pilot production was initiated at Incom, Inc. in 2018. The Gen-I LAPPD utilizes a stripline anode for direct charge readout. The novel Gen-II LAPPD employs an internal resistive thin-film which capacitively couples to a customizable external signal readout board, streamlining production. The Gen-II LAPPD, with an active area of 373 cm${}^2$, is capable of high single photoelectron (PE) gain of $\sim$10${}^7$, low dark rates ($\sim$1 kHz/cm${}^2$), single PE timing resolution of $\sim$65 ps, and $\mathcal{O}$(mm) position resolution. Coupled with a UV-grade fused silica window, the LAPPD features a high quantum efficiency (QE) bialkali photocathode of $>$30% with spectral response down to $\sim$165 nm. The LAPPD is an excellent candidate for electromagnetic calorimeter (ECAL) timing layers, photon-based neutrino detectors, high energy collider experiments, medical imaging systems, and nuclear non-proliferation applications.

   ↳ physics.ins-dethep-exnucl-exphysics.med-phJINST(2024)·13 citations
6. 06*

   Monitoring Spent Nuclear Fuel in a Dry Cask Using Momentum Integrated Muon Scattering Tomography

   Junghyun Bae🇺🇸 · Stylianos Chatzidakis🇺🇸

   Nuclear materials accountability and nonproliferation are among the critical tasks to be addressed for the advancement of nuclear energy in the United States. Monitoring spent nuclear fuel is important to continue reliable stewardship of SNF storage. Cosmic ray muons have been acknowledged a promising radiographic tool for monitoring SNF due to their highly penetrative nature and high energy. Cosmic ray muons are more suitable and have been used for imaging large and dense objects. Despite their potential in various applications, the wide application of cosmic ray muons is limited by the naturally low intensity at sea level. To efficiently utilize cosmic ray muons in engineering applications, trajectory and momentum must be measured. Although various studies demonstrate that there is significant potential for measuring momentum in muon applications, it is still difficult to measure both muon scattering angle and momentum in the field. To fill this critical gap, a muon spectrometer using multilayer pressurized gas Cherenkov radiators was proposed. However, existing muon tomographic algorithms were developed assuming monoenergetic muon scattering and are not optimized for a measured polyenergetic momentum spectrum. In this work, we develop and evaluate a momentum integrated muon scattering tomography algorithm. We evaluate the algorithm on its capability to identify a missing fuel assembly from a SNF dry cask. Our results demonstrate that image resolution using MMST is significantly improved when measuring muon momentum and it can reduce monitoring time by a factor of 10 when compared to that of a conventional muon imaging technique in terms of systematically finding a missing FA.

   ↳ physics.ins-detnucl-ex0 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.