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Nuclear Theory·nucl-th

Monday·March 27, 2023

7 papers—3 primary·4 cross-listed

All7Primary3Cross-lists4
  1. 01

    [Submitted on 23 Mar 2023]

    The Gallium Neutrino Absorption Cross Section and its Uncertainty

    S. R. Elliott🇺🇸 · V.N. Gavrin🇷🇺 · W. C. Haxton🇺🇸 · T. V. Ibragimova🇷🇺 · E. J. Rule🇺🇸

    In the recent Baksan Experiment on Sterile Transitions (BEST), a suppressed rate of neutrino absorption on a gallium target was observed, consistent with earlier results from neutrino source calibrations of the SAGE and GALLEX/GNO solar neutrino experiments. The BEST collaboration, utilizing a 3.4 MCi 51Cr neutrino source, found observed-to-expected counting rates at two very short baselines of R=0.791 plus/minus 0.05 and 0.766 plus/minus 0.05, respectively. Among recent neutrino experiments, BEST is notable for the simplicity of both its neutrino spectrum, line neutrinos from an electron-capture source whose intensity can be measured to a estimated precision of 0.23%, and its absorption cross section, where the precisely known rate of electron capture to the gallium ground state, 71Ge(e,nue)71Ga(g.s.), establishes a minimum value. However, the absorption cross section uncertainty is a common systematic in the BEST, SAGE, and GALLEX/GNO neutrino source experiments. Here we update that cross section, considering a variety of electroweak corrections and the role of transitions to excited states, to establish both a central value and reasonable uncertainty, thereby enabling a more accurate assessment of the statistical significance of the gallium anomalies. Results are given for 51Cr and 37Ar sources. The revised neutrino capture rates are used in a re-evaluation of the BEST and gallium anomalies.

    Comments:
    21 pages, 5 figures; Report number added in this revision
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2303.13623 [pdf]
    PRC(2023)·25 citations
  2. 02

    [Submitted on 24 Mar 2023]

    Systematic analysis of the nuclear absorption effect on the cross section of the knockout reaction

    Sang-In Shim · Kazuki Yoshida · Kazuyuki Ogata

    Recent studies on nucleon and alpha knockout reactions have shown that the distorted-wave impulse approximation (DWIA) is a simple and accurate method to describe these reactions. As it has been argued for decades, the nuclear absorption is one of the most important ingredients of the DWIA calculation. In this work, we systematically investigate the absorption effects on the cross sections of the nucleon and alpha knockout reactions. To do this, we calculate the ratio of the cross sections of the DWIA and plane-wave impulse approximation (PWIA) and examine its dependence on the mass number and single-particle orbital of the knocked-out particles. We will discuss the specific characteristics of the absorption effect for each reaction.

    Comments:
    8 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2303.13841 [pdf]
    J.Phys.Soc.Jap.(2023)·0 citations
  3. 03

    [Submitted on 24 Mar 2023]

    JEWEL on a (2+1)D background with applications to small systems and substructure

    Isobel Kolbé🇪🇸

    High- jets are an important tool for characterizing the quark-gluon plasma (QGP) created in heavy-ion collisions. However, a precise understanding of the jet-medium interaction is still lacking, and the development of more sophisticated observables is needed. This work presents a tool that allows for the exploration of alternative high- observables in a variety of collision systems. The tool builds on the publicly available JEWEL Monte Carlo code, and allows for the evolution of a jet on any given (2+1)-dimensional background. Proof-of-concept observables are also presented, studied using the latest version of JEWEL, JEWEL-2.4.0. The simplicity of the separation of the physics of the jet from the physics of the medium (while still allowing for the usual JEWEL medium-response), allows for easy interpretation without the need for complex parameterization. Results are produced using the RIVET toolkit, which allows for transparent preservation and development of analyses that are compatible with experimental methods. The code and analysis used to produce the plots presented here are made publicly available on a Github repository, with up-to-date usage instructions. This tool is expected to be useful to the broad jet-physics community for the study of precision observables for jets.

    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2303.14166 [pdf]
    14 citations
  4. 04

    [Submitted on 23 Mar 2023] (cross-list from hep-ph)

    The isospin-3 three-particle -matrix at NLO in ChPT

    Jorge Baeza-Ballesteros (IFIC, Valencia)🇪🇸 · Johan Bijnens (Lund U.)🇸🇪 · Tomáš Husek (Lund U. and Charles U.)🇨🇿 · Fernando Romero-López (MIT)🇺🇸 · Stephen R. Sharpe (Washington U.)🇺🇸 · Mattias Sjö (Lund U.)🇸🇪

    The three-particle -matrix, , is a scheme-dependent quantity that parametrizes short-range three-particle interactions in the relativistic-field-theory three-particle finite-volume formalism. In this work, we compute its value for systems of three pions at maximal isospin through next-to-leading order (NLO) in Chiral Perturbation Theory (ChPT). We compare the values to existing lattice QCD results and find that the agreement between lattice QCD data and ChPT in the first two coefficients of the threshold expansion of is significantly improved with respect to leading order once NLO effects are incorporated.

    Comments:
    57 pages, 12 figures, 2 tables; v2: added sec. 2.3, minor changes, typos corrected, conclusions unchanged, version published in JHEP
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2303.13206 [pdf]
    JHEP(2023)·25 citations
  5. 05

    [Submitted on 23 Mar 2023] (cross-list from hep-ph)

    High-energy neutrino deep inelastic scattering cross sections

    Keping Xie🇺🇸 · Jun Gao🇨🇳 · T. J. Hobbs🇺🇸 · Daniel R. Stump🇺🇸 · C.-P. Yuan🇺🇸

    We present a state-of-the-art prediction for cross sections of neutrino deep inelastic scattering (DIS) from nucleon at high neutrino energies, , from 100 GeV to 1000 EeV ( GeV). Our calculations are based on the latest CT18 NNLO parton distribution functions (PDFs) and their associated uncertainties. In order to make predictions for the highest energies, we extrapolate the PDFs to small according to several procedures and assumptions, thus affecting the uncertainties at ultra-high ; we quantify the uncertainties corresponding to these choices. Similarly, we quantify the uncertainties introduced by the nuclear corrections which are required to evaluate neutrino-nuclear cross sections for neutrino telescopes. These results can be applied to currently-running astrophysical neutrino observatories, such as IceCube and KM3NeT, as well as various future experiments which have been proposed.

    Comments:
    57 pages, 27 figures, and 2 tables
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2303.13607 [pdf]
    PRD(2024)·34 citations
  6. 06

    [Submitted on 23 Mar 2023] (cross-list from hep-ph)

    Small- Factorization from Effective Field Theory

    Duff Neill🇺🇸 · Aditya Pathak🇺🇸 · Iain Stewart🇺🇸

    We derive a factorization theorem that allows for resummation of small- logarithms by exploiting Glauber operators in the soft collinear effective field theory. Our analysis is carried out for the hadronic tensor in deep inelastic scattering, and leads to the definition of a new gauge invariant soft function that describes quark and gluon emission in the central region. This soft function provides a new framework for extending resummed calculations for coefficient functions to higher logarithmic orders. Our factorization also defines impact factors by universal collinear functions that are process independent, for instance being identical in small- DIS and Drell-Yan.

    Comments:
    43 pgs
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2303.13710 [pdf]
    JHEP(2023)·13 citations
  7. 07

    [Submitted on 23 Mar 2023] (cross-list from astro-ph.HE)

    A tight universal relation between the shape eccentricity and the moment of inertia for rotating neutron stars

    Yong Gao · Lijing Shao · Jan Steinhoff

    Universal relations that are insensitive to the equation of state (EoS) are useful in reducing the parameter space when measuring global quantities of neutron stars (NSs). In this paper, we reveal a new universal relation that connects the eccentricity to the radius and moment of inertia of rotating NSs. We demonstrate that the universality of this relation holds for both conventional NSs and bare quark stars (QSs) in the slow rotation approximation, albeit with different relations. The maximum relative deviation is approximately for conventional NSs and for QSs. Additionally, we show that the universality still exists for fast-rotating NSs if we use the dimensionless spin to characterize their rotation. The new universal relation will be a valuable tool to reduce the number of parameters used to describe the shape and multipoles of rotating NSs, and it may also be used to infer the eccentricity or moment of inertia of NSs in future X-ray observations.

    Comments:
    7 pages, 5 figures; accepted by ApJ
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
    arXiv:
    2303.14130 [pdf]
    ApJ(2023)·9 citations

Affiliations

first authorsco-authorsvia INSPIRE