PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·January 4, 2024

5 papers—1 primary·4 cross-listed

All5Primary1Cross-lists4
  1. 02

    [Submitted on 1 Jan 2024] (cross-list from hep-ph)

    Constraining MeV to 10 GeV majoron by Big Bang Nucleosynthesis

    Sanghyeon Chang🇰🇷 · Sougata Ganguly🇰🇷 · Tae Hyun Jung🇰🇷 · Tae-Sun Park🇰🇷 · Chang Sub Shin🇰🇷

    We estimate the Big Bang nucleosynthesis (BBN) constraint on the majoron in the mass range between to which dominantly decays into the standard model neutrinos. When the majoron lifetime is shorter than , the injected neutrinos mainly heat up background plasma, which alters the relation between photon temperature and background neutrino temperature. For a lifetime longer than , most of the injected neutrinos directly contribute to the protons-to-neutrons conversion. In both cases, deuterium and helium abundances are enhanced, while the constraint from the deuterium is stronger than that from the helium. abundance gets decreased as a consequence of additional neutrons, but the parameter range that fits the observed abundance is excluded by the deuterium constraint. We also estimate other cosmological constraints and compare them with the BBN bound.

    Comments:
    12 pages, 3 figures, v2: major revision made by including correct n/p conversion induced by modified thermal neutrinos, slight changes in the result, references added, version accepted in PRD
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2401.00687 [pdf]
    PRD(2024)·17 citations
  2. 03

    [Submitted on 15 Dec 2023] (cross-list from hep-ph)

    Heavy-flavor transport and hadronization in a small fireball

    Andrea Beraudo🇮🇹 · Arturo De Pace🇮🇹 · Daniel Pablos🇮🇹 · Francesco Prino🇮🇹 · Marco Monteno🇮🇹 · Marzia Nardi🇮🇹

    We study heavy-flavor hadron production in high-energy pp collisions, assuming the formation of a small, deconfined and expanding fireball where charm quarks can undergo rescattering and hadronization. We adopt the same in-medium hadronization mechanism developed for heavy-ion collisions, which involves Local Color-Neutralization (LCN) through recombination of charm quarks with nearby opposite color charges from the background fireball. Diquark excitations in the hot medium favor the formation of charmed baryons. The recombination process, involving closely aligned partons from the same fluid cell, effectively transfers the collective flow of the system to the final charmed hadrons. This framework can qualitatively reproduce the observed experimental findings in heavy-flavor particle-yield ratios, -spectra and elliptic-flow coefficients. Our results provide new, complementary support to the idea that the collective phenomena observed in small systems have the same origin as those observed in heavy-ion collisions.

    Comments:
    Parallel talk at Quark Matter 2023
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2401.01360 [pdf]
    EPJ Web Conf.(2024)·0 citations
  3. 04

    [Submitted on 3 Jan 2024] (cross-list from cond-mat.str-el)

    Conservation, crossing symmetry, and completeness in diagrammatic theories

    Frederick Green

    The diagrammatic analysis of interacting particle assemblies harbors a fundamental mismatch between two of its main implementations: Phi-derivable (conserving) approximations and parquet (crossing symmetric) models. No termwise expansion, short of the exact theory itself, can be both conserving and crossing symmetric. This work applies the Kraichnan embedded-Hamiltonian formalism for strongly coupled systems to investigate consistency of the interplay between purely pair-mediated correlations and pair-irreducible ones. The approach sheds a different light on the issue of crossing symmetry versus conservation. In the process, the parquet equations acquire a different formulation.

    Comments:
    18pp, 11 figures, corrects some notational inconsistencies
    Subjects:
    Strongly Correlated Electrons (cond-mat.str-el); Nuclear Theory (nucl-th)
    arXiv:
    2401.01682 [pdf]
    PRA(2024)·1 citation
  4. 05

    [Submitted on 3 Jan 2024] (cross-list from hep-ph)

    Transverse momentum balance of dijets in Xe+Xe collisions at the LHC

    Yao Li🇨🇳 · Shu-Wan Shen🇨🇳 · Sa Wang🇨🇳 · Ben-Wei Zhang🇨🇳

    We present a theoretical study of the medium modifications of the balance () of dijets in Xe+Xe collisions at TeV. The initial production of dijets was carried out using the POWHEG+PYTHIA8 prescription, which matches the next-to-leading-order (NLO) QCD matrix elements with the parton shower (PS) effect. The SHELL model described the in-medium evolution of nucleus-nucleus collisions using a transport approach. The theoretical results of the dijet in the Xe+Xe collisions exhibit more imbalanced distributions than those in the p+p collisions, consistent with recently reported ATLAS data. By utilizing the Interleaved Flavor Neutralisation, an infrared-and-collinear-safe jet flavor algorithm, to identify the flavor of the reconstructed jets, we classify dijets processes into three categories: gluon-gluon (), quark-gluon (), and quark-quark (), and investigated the respective medium modification patterns and fraction changes of the , , and components of the dijet sample in Xe+Xe collisions. It is shown that the increased fraction of component at a small contributes to the imbalance of the dijet; in particular, the (quark-jet-leading) dijets experience more significant asymmetric energy loss than the (gluon-jet-leading) dijets traversing the QGP. By comparing the of inclusive, and dijets in Xe+Xe collisions, we observe . Moreover, , the ratios of the nuclear modification factors of dijets in Xe+Xe to those in Pb+Pb, were calculated, which indicates that the yield suppression of dijets in Pb+Pb is more pronounced than that in Xe+Xe owing to the larger radius of the lead nucleus.

    Comments:
    8 pages, 6 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2401.01706 [pdf]
    Nucl.Sci.Tech.(2024)·17 citations

Affiliations

first authorsco-authorsvia INSPIRE