PaperPanorama
FAQ

Nuclear Theory·nucl-th

Wednesday·February 22, 2023

6 papers—2 primary·4 cross-listed

All6Primary2Cross-lists4
  1. 01

    [Submitted on 21 Feb 2023]

    Beam Energy Dependence of the Linear and Mode-Coupled Flow Harmonics Using the A Multi-Phase Transport Model

    Niseem Magdy🇺🇸

    In the framework of the A Multi-Phase Transport (AMPT) model, the multi-particle azimuthal cumulant method is used to calculate the linear and mode-coupled contributions to the quadrangular flow harmonic (), mode-coupled response coefficient as a function of centrality in Au+Au collisions at = 200, 39, 27 and 19.6 GeV. This study indicated that the linear and mode-coupled contributions to the are sensitive to the beam energy change. Nevertheless, the correlations between different order flow symmetry planes and the mode-coupled response coefficients show a weak beam energy dependence. In addition, the presented results suggest that the experimental measurements that span a broad range of beam energies can be an additional constraint for the theoretical models' calculations.

    Comments:
    5 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2302.10373 [pdf]
    Universe(2023)·4 citations
  2. 02

    [Submitted on 21 Feb 2023]

    Attractors for Flow Observables in 2+1D Bjorken Flow

    Victor E. Ambruş🇷🇴 · Sören Schlichting🇩🇪 · Clemens Werthmann🇩🇪

    We examine the capabilities of second-order Israel-Stewart-type hydrodynamics to capture the early-time behaviour of the quark-gluon plasma created in heavy-ion collisions. We point out that at very early times, the dynamics of the fireball is governed by the local 0+1-D Bjorken flow attractor due to the rapid expansion along the longitudinal direction. Discrepancies between hydrodynamics and kinetic theory in this far-from-equilibrium regime leads to disagreement at the level of late-time observables, such as elliptic flow. We show that rescaling the initial energy-density profile for hydrodynamics accounts for such discrepancies, restoring agreement with kinetic theory for large opacities (small shear viscosity / large system size / high energy).

    Comments:
    6 pages, 3 figures. Contribution to the TIM-2022 conference proceedings
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Fluid Dynamics (physics.flu-dyn)
    arXiv:
    2302.10618 [pdf]
    AIP Conf.Proc.(2024)·3 citations
  3. 03

    [Submitted on 20 Feb 2023] (cross-list from hep-ph)

    Probing the dark sector with nuclear transition photons

    Bhaskar Dutta🇺🇸 · Wei-Chih Huang🇺🇸 · Jayden L. Newstead🇦🇺

    Here we present world-leading sensitivity to light ( MeV) dark matter (DM) using beam-dump experiments. Dark sector particles produced during pion decay at accelerator beam-dumps can be detected via scattering in neutrino detectors. The decay of nuclei excited by the inelastic scattering of DM is an unexploited channel which has significantly better sensitivity than similar searches using the elastic scattering channel. We show that this channel is a powerful probe of DM by demonstrating sensitivity to the thermal relic abundance benchmark in a scalar DM dark-photon portal model. This is achieved through the use of existing data, obtained by the KARMEN experiment over two decades ago, which allow us to set world-leading constraints on this model over a wide mass range. With experimental improvements planned for the future, this technique will be able to probe the thermal relic benchmark for fermionic DM across a wide mass range.

    Comments:
    5 pages, 4 figures. V2 updated with bounds from KARMEN and projections for PIP2BD. V3 as accepted by PRL
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2302.10250 [pdf]
    PRL(2023)·15 citations
  4. 04

    [Submitted on 21 Feb 2023] (cross-list from hep-ph)

    Reaction plane alignment with linearly polarized photon in heavy-ion collisions

    Xin Wu🇨🇳 · Xinbai Li🇨🇳 · Zebo Tang🇨🇳 · Pengfei Wang🇨🇳 · Wangmei Zha🇨🇳

    The collective observables play critical roles in probing the properties of quark-gluon-plasma created in relativistic heavy-ion collisions, in which the information on initial collision geometry is crucial. However, the initial collision geometry, e.g., the reaction plane, cannot be directly extracted in the experiment. In this paper, we demonstrate the idea of determining the reaction plane via the feature of linear polarization of the coherent photoproduction process and discuss the advantages of the proposed approach in comparison with traditional methods.

    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2302.10458 [pdf]
    PRResearch(2022)·22 citations
  5. 05

    [Submitted on 21 Feb 2023] (cross-list from hep-ph)

    Dissociation rates and recombination likelihood of bottomonium states in heavy-ion collisions at = 5.02 TeV

    Abdulla Abdulsalam🇸🇦 · Mohsin Ilahi🇮🇳 · Lana Alabbasi🇸🇦 · Rafeeda Kassim🇭🇺

    In the medium of relativistic heavy-ion collisions, dissociation of the quarkonium and their survival have been studied to understand the properties of Quark Gluon Plasma (QGP). The coupled rates of dissociation and recombination reactions in QGP are commonly solved with the Boltzmann transport equation in which the formation and dissociation reactions compete with each other. Since the dissociation of newly formed bound-states is not accounted in the Boltzmann equation, a framework of decoupled rates is developed to assess the combined effect of gluon-induced dissociation and recombination (though it is small for ) together with color screening on bottomonium production in heavy-ion collisions at center of mass energy () = 5.02 TeV. To calculate the recombination rates, we have employed an effective method of Bateman solution which makes sure the correlated effect between the recombination and the dissociation of the newly combined bottomonium in the QGP medium. The modifications of bottomonium have been estimated in an inflating QGP with the constraints matching with the dynamics of Pb+Pb collision events at LHC.

    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2302.10611 [pdf]
    Int.J.Mod.Phys.A(2023)·3 citations
  6. 06

    [Submitted on 21 Feb 2023] (cross-list from hep-ph)

    Phases of cold holographic QCD: baryons, pions and rho mesons

    Nicolas Kovensky🇫🇷 · Aaron Poole🇰🇷 · Andreas Schmitt🇬🇧

    We improve the holographic description of isospin-asymmetric baryonic matter within the Witten-Sakai-Sugimoto model by accounting for a realistic pion mass, computing the pion condensate dynamically, and including rho meson condensation by allowing the gauge field in the bulk to be anisotropic. This description takes into account the coexistence of baryonic matter with pion and rho meson condensates. Our main result is the zero-temperature phase diagram in the plane of baryon and isospin chemical potentials. We find that the effective pion mass in the baryonic medium increases with baryon density and that, as a consequence, there is no pion condensation in neutron-star matter. Our improved description also predicts that baryons are disfavored at low baryon chemical potentials even for arbitrarily large isospin chemical potential. Instead, rho meson condensation sets in on top of the pion condensate at an isospin chemical potential of about . We further observe a highly non-monotonic phase boundary regarding the disappearance of pion condensation.

    Comments:
    31 pages, 7 figures, v3: typos corrected, version to appear in SciPost Phys; v2: new ansatz for the bulk gauge field, eliminating an unjustified assumption in v1; as a consequence, numerous modifications in text, equations, and plots, with main conclusions unchanged
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2302.10675 [pdf]
    SciPost Phys.(2023)·22 citations

Affiliations

first authorsco-authorsvia INSPIRE