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Nuclear Theory·nucl-th

Friday·July 22, 2022

6 papers—2 primary·4 cross-listed

All6Primary2Cross-lists4
  1. 01

    [Submitted on 20 Jul 2022]

    Theoretical evaluation of solar proton-proton fusion reaction rate and its uncertainties

    Hilla De-Leon🇮🇱 · Doron Gazit🇮🇱

    The weak proton-proton fusion into a deuteron (H) is the driving reaction in the energy production in the Sun, as well as similar main sequence stars. Its reaction rate in the solar interior is determined only theoretically. Here, we provide a new determination of the rate of this reaction in solar conditions , and analyze theoretical and experimental sources for uncertainties, using effective field theory of quantum chromo-dynamics without explicit pions at next-to-leading order. We find an enhancement of by over the previously recommended value. This change reduces the calculated fluxes of neutrinos originating in B and Be nuclear reactions in the Sun, thus favoring higher abundances for metallic photospheric elements, in the tension between different composition determination, known as the ``Solar Composition Problem''.

    Comments:
    9 pages, 3 figures
    Subjects:
    Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR)
    arXiv:
    2207.10176 [pdf]
    PLB(2023)·7 citations
  2. 02

    [Submitted on 21 Jul 2022]

    Triaxiality explored by an odd quasi-particle

    Weichuan Li · Mark A. Caprio · Stefan Frauendorf

    The triaxiality of odd-mass nuclei is investigated by coupling a quasiparticle to an even-even core through the core-quasiparticle coupling model. Both soft and rigid triaxial cores are considered. The "soft core" is described by the collective model with rotation-vibrational motion, while the "rigid core" is described by the triaxial rotor model, which is a limiting case of the collective model with only rotational motion. We show that the presence of the odd quasiparticle modifies the collective quadrupole dynamics of the core to appear more "rigid".

    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2207.10266 [pdf]
    5 citations
  3. 03

    [Submitted on 20 Jul 2022] (cross-list from hep-ph)

    Tackling the infamous term of the QCD pressure

    Pablo Navarrete🇨🇱 · York Schröder🇨🇱

    We report on ongoing efforts to tackle an important open problem in QCD thermodynamics, namely an evaluation of the pressure to order in a weak-coupling expansion, corresponding to four loops. In particular, we identify a class of contributing Feynman sum-integrals with lower-loop factors, describe the formalism to tensor decompose those, and manage to map them onto scalar master sum-integrals that have already been evaluated in the literature.

    Comments:
    10 pages, 1 figure. Contribution to the proceedings of "Loops and Legs in Quantum Field Theory" (LL2022), Ettal, Germany; v2 to match the published version
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2207.10151 [pdf]
    PoS(2022)·7 citations
  4. 04

    [Submitted on 21 Jul 2022] (cross-list from hep-ph)

    Multiparticle production in proton-nucleus collisions beyond eikonal accuracy

    Pedro Agostini🇪🇸 · Tolga Altinoluk🇵🇱 · Néstor Armesto🇪🇸 · Fabio Dominguez🇪🇸 · José Guilherme Milhano🇵🇹

    We study the effects on multigluon production at mid-rapidity in the Color Glass Condensate of the non-eikonal corrections that stem from relaxing the shockwave approximation and giving the target a finite size. We extend previous works performed in the dilute-dilute approximation suitable for proton-proton collisions, to the dilute-dense one applicable to proton-nucleus. We employ the McLerran-Venugopalan model for the projectile averages. For the target averages, we use the Golec-Biernat--Wüsthoff model and restrict to the leading contributions in overlap area that allow a factorization of ensembles of Wilson lines into products of dipoles. We make the connection with the jet quenching formalism and compare with previous results in the literature, providing a parametrization of the so-called decorated dipoles. We show that the non-eikonal effects on single inclusive particle production, contrary to what happens in jet quenching, are only sizable, of a few percent, for modest energies GeV and central rapidities. On the other hand, we find that the effects on double inclusive gluon production are larger for the same kinematics. We show that, as found previously in the dilute-dilute situation, non-eikonal corrections break the accidental symmetry in the CGC, allowing for the existence of non-vanishing odd azimuthal harmonics.

    Comments:
    43 pages, 6 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2207.10472 [pdf]
    EPJC(2022)·26 citations
  5. 05

    [Submitted on 21 Jul 2022] (cross-list from hep-ph)

    First row CKM unitarity

    Chien-Yeah Seng🇩🇪

    In this talk I briefly review the precision test of the first row CKM unitarity, focusing mainly on and extracted from pion, kaon, neutron and superallowed nuclear beta decays. I will discuss the current status of several important Standard Model theory inputs to these processes, and the need for future improvements.

    Comments:
    References added
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2207.10492 [pdf]
    3 citations
  6. 06

    [Submitted on 21 Jul 2022] (cross-list from hep-ph)

    and global polarization from the core-corona model

    Alejandro Ayala🇲🇽 · Isabel Domínguez🇲🇽 · Ivonne Maldonado🇷🇺 · Maria Elena Tejeda-Yeomans🇲🇽

    We report on work aimed to describe the and global polarizations in a heavy-ion collision environment using the core-corona model, where the source of these hyperons is a high-density core and a less dense corona. We show that the overall properties of the polarization excitation functions can be linked to the relative abundance of s and s coming from the core versus those coming from the corona. Both global polarizations peak at collision energies GeV. The exact positions and heights of these peaks depend not only on a reversal of relative abundances with collision energy, but also on the centrality class, both related to the QGP volume and lifetime.

    Comments:
    Proceedings for the 37th Winter Workshop on Nuclear Dynamics
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2207.10560 [pdf]
    Rev.Mex.Fis.Suppl.(2022)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE