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Nuclear Theory·nucl-th

Friday·February 19, 2021

4 papers—1 primary·3 cross-listed

All4Primary1Cross-lists3
  1. 02

    [Submitted on 17 Feb 2021] (cross-list from hep-ex)

    Collider constraints on axion-like particles

    David d'Enterria🇨🇭

    The current status and future prospects of searches for axion-like particles (ALPs) at colliders, mostly focused on the CERN LHC, are summarized. Constraints on ALPs with masses above a few GeV that couple to photons, as well as to Z or Higgs bosons, have been set at the LHC through searches for new resonances in di-, tri-, and four-photon final states. Inclusive and exclusive diphotons in proton-proton and lead-lead collisions, pp, PbPb , as well as exotic Z and Higgs boson decays, pp and pp , have been analyzed. Exclusive searches in PbPb collisions provide the best exclusion limits for ALP masses 100 GeV, whereas the other channels are the most competitive ones over GeV2.6 TeV. Integrated ALP production cross sections up to 100 nb are excluded at 95% confidence level, corresponding to constraints on axion-photon couplings down to 0.05 TeV, over broad mass ranges. Factors of 10100 improvements in these limits are expected at the LHC approaching TeV over GeV5 TeV in the next decade.

    Comments:
    11 pages, 8 plots, extended contribution to the 'Feebly-Interacting Particles (FIPs) 2020 Workshop Report'
    Subjects:
    High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2102.08971 [pdf]
    87 citations
  2. 03

    [Submitted on 18 Feb 2021] (cross-list from nucl-ex)

    Electron-Ion Collider in China

    Daniele P. Anderle🇨🇳 · Valerio Bertone🇫🇷 · Xu Cao🇨🇳 · Lei Chang🇨🇳 · Ningbo Chang🇨🇳 · Gu Chen🇨🇳 · Xurong Chen🇨🇳 · Zhuojun Chen🇨🇳 · Zhufang Cui🇨🇳 · Lingyun Dai🇨🇳 · Weitian Deng🇨🇳 · Minghui Ding🇮🇹 and 90 other authors

    Lepton scattering is an established ideal tool for studying inner structure of small particles such as nucleons as well as nuclei. As a future high energy nuclear physics project, an Electron-ion collider in China (EicC) has been proposed. It will be constructed based on an upgraded heavy-ion accelerator, High Intensity heavy-ion Accelerator Facility (HIAF) which is currently under construction, together with a new electron ring. The proposed collider will provide highly polarized electrons (with a polarization of 80%) and protons (with a polarization of 70%) with variable center of mass energies from 15 to 20 GeV and the luminosity of (2-3) 10 cm s. Polarized deuterons and Helium-3, as well as unpolarized ion beams from Carbon to Uranium, will be also available at the EicC. The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region, including 3D tomography of nucleon; the partonic structure of nuclei and the parton interaction with the nuclear environment; the exotic states, especially those with heavy flavor quark contents. In addition, issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC. In order to achieve the above-mentioned physics goals, a hermetical detector system will be constructed with cutting-edge technologies. This document is the result of collective contributions and valuable inputs from experts across the globe. The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States. The success of this project will also advance both nuclear and particle physics as well as accelerator and detector technology in China.

    Comments:
    EicC white paper, written by the whole EicC working group
    Subjects:
    Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2102.09222 [pdf]
    Front.Phys.(Beijing)(2021)·601 citations
  3. 04

    [Submitted on 18 Feb 2021] (cross-list from hep-th)

    Covariant tetraquark equations in quantum field theory

    A. N. Kvinikhidze🇬🇪 · B. Blankleider🇦🇺

    We derive general covariant coupled equations of QCD describing the tetraquark in terms of a mix of four-quark states , and two-quark states . The coupling of to states is achieved by a simple contraction of a four-quark -irreducible Green function down to a two-quark Bethe-Salpeter kernel. The resulting tetraquark equations are expressed in an exact field theoretic form, and are in agreement with those obtained previously by consideration of disconnected interactions; however, despite being more general, they have been derived here in a much simpler and more transparent way.

    Comments:
    12 pages, 5 figures
    Subjects:
    High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2102.09558 [pdf]
    PRD(2022)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE