Fri·May 6, 2022Friday·May 6, 2022

1. 01*

   Fill and dump measurement of the neutron lifetime using an asymmetric magneto-gravitational trap

   C. Cude-Woods · F. M. Gonzalez · E. M. Fries · T. Bailey · M. Blatnik · N. B. Callahan · J. H. Choi · S. M. Clayton · S. A. Currie · M. Dawid · B. W. Filippone · W. Fox and 31 other authors

   The past two decades have yielded several new measurements and reanalyses of older measurements of the neutron lifetime. These have led to a 4.4 standard deviation discrepancy between the most precise measurements of the neutron decay rate producing protons in cold neutron beams and the lifetime measured in neutron storage experiments. Measurements using different techniques are important for investigating whether there are unidentified systematic effects in any of the measurements. In this paper we report a new measurement using the Los Alamos asymmetric magneto-gravitational trap where the surviving neutrons are counted external to the trap using the fill and dump method. The new measurement gives a free neutron lifetime of . Although this measurement is not as precise, it is in statistical agreement with previous results using in situ counting in the same apparatus.

   nucl-exphysics.ins-detPRC(2022)·4 citations
2. 02*

   Inverse Tritium Beta Decay with Relic Neutrinos, Solar Neutrinos, and a 51Cr Source

   Jen-Chieh Peng🇺🇸 · Gordon Baym🇺🇸

   The inverse tritium beta decay (ITBD) reaction, ${\nu }_e{+}^3$H $\to e^{-}{+}^3$He, is a promising experimental tool for observing relic neutrinos created in the early Universe. This reaction has been selected by the PTOLEMY experiment for the search of relic neutrinos. Despite its potential, the ITBD reaction induced by any sources of neutrinos has yet to be observed. We show that an intense ${}^{51}$Cr radioactive neutrino source is suitable for observing the ITBD reaction for the first time. As the Sun is another source of intense electron neutrinos, we also examine the ITBD reaction rate from solar neutrinos. Based on our recent studies on the evolution of the helicity of relic neutrinos, we further present the ITBD rate for capturing relic neutrinos as a function of neutrino mass hierarchy, the Dirac versus Majorana nature of neutrino, and the mass of the lightest neutrino.

   ↳ hep-phastro-ph.HEhep-exnucl-exPRD(2022)·4 citations
3. 03*

   Evolution of global polarization in relativistic heavy-ion collisions within a perturbative approach

   Xiaowen Li🇨🇳 · Ze-Fang Jiang🇨🇳 · Shanshan Cao🇨🇳 · Jian Deng🇨🇳

   Extremely large angular orbital momentum can be produced in non-central heavy-ion collisions, leading to a strong transverse polarization of partons that scatter through the quark-gluon plasma (QGP) due to spin-orbital coupling. We develop a perturbative approach to describe the formation and spacetime evolution of quark polarization inside the QGP. Polarization from both the initial hard scatterings and interactions with the QGP have been consistently described using the quark-potential scattering approach, which has been coupled to realistic initial condition calculation and the subsequent (3+1)-dimensional viscous hydrodynamic simulation of the QGP for the first time. Within this improved approach, we have found that different spacetime-rapidity-dependent initial energy density distributions generate different time evolution profiles of the longitudinal flow velocity gradient of the QGP, which further lead to an approximately 15% difference in the final polarization of quarks collected on the hadronization hypersurface of the QGP. Therefore, in addition to the collective flow coefficients, the hyperon polarization may serve as a novel tool to help constrain the initial condition of the hot nuclear matter created in high-energy nuclear collisions.

   ↳ nucl-thhep-phnucl-exEPJC(2023)·11 citations
4. 04*

   Convolutional Auto-Encoders for Drift Chamber data de-noising for CLAS12

   Gagik Gavalian🇺🇸 · Polykarpos Thomadakis🇺🇸 · Angelos Angelopoulos🇺🇸 · Nikos Chrisochoides🇺🇸

   In this article, we present the results of using Convolutional Auto-Encoders for de-noising raw data for CLAS12 drift chambers. The de-noising neural network provides increased efficiency in track reconstruction and also improved performance for high luminosity experimental data collection. The de-noising neural network used in conjunction with the previously developed track classifier neural network \cite{Gavalian:2022hfa} lead to a significant track reconstruction efficiency increase for current luminosity ($0.6\times 10^{35}c{m}^{-2}se{c}^{-1}$ ). The increase in experimentally measured quantities will allow running experiments at twice the luminosity with the same track reconstruction efficiency. This will lead to huge savings in accelerator operational costs, and large savings for Jefferson Lab and collaborating institutions.

   ↳ physics.ins-detnucl-ex1 citation

* 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.