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Nuclear Theory·nucl-th

Thursday·April 29, 2021

7 papers—2 primary·5 cross-listed

All7Primary2Cross-lists5
  1. 01

    [Submitted on 28 Apr 2021]

    The interaction constrained by recent hypernuclei experiments

    Jinniu Hu🇨🇳 · Ying Zhang🇨🇳 · Hong Shen🇨🇳

    The interaction is investigated in the quark mean-field (QMF) model based on recent observables of the () system. The experimental data about the binding energy of -state hyperon in hypernuclei at KISO, IBUKI, E07-T011, E176-14-03-35 events are conflated as MeV. With this constraint, the coupling strengths between the vector meson and hyperon are fixed in three QMF parameter sets. Meanwhile, the binding energy of state in is predicted as MeV with the same interactions, which are completely consistent with the data from the KINKA and IRRAWADDY events. Finally, the single potential is calculated in the symmetric nuclear matter in the framework of QMF models. It is MeV at nuclear saturation density, which will contribute to the study on the strangeness degree of freedom in compact star.

    Comments:
    12pages, 4 figures, 2 tables
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2104.13567 [pdf]
    J.Phys.G(2022)·16 citations
  2. 02

    [Submitted on 28 Apr 2021]

    The sound speed and core of massive compact stars: A manifestation of hadron-quark duality

    Yong-Liang Ma🇨🇳 · Mannque Rho🇫🇷

    When baryon-quark continuity is formulated in terms of a topology change without invoking "explicit " QCD degrees of freedom at a density higher than twice the nuclear matter density the core of massive compact stars can be described in terms of fractionally charged particles, behaving neither like pure baryons nor deconfined quarks. Hidden symmetries, both local gauge and pseudo-conformal (or broken scale), lead to the pseudo-conformal (PC) sound velocity at in compact stars. We argue these symmetries are "emergent" from strong nuclear correlations and conjecture that they reflect hidden symmetries in QCD proper exposed by nuclear correlations. We establish a possible link between the quenching of in superallowed Gamow-Teller transitions in nuclei and the precocious onset at of the PC sound velocity predicted at the dilaton limit fixed point. We propose that bringing in explicit quark degrees of freedom as is done in terms of the "quarkyonic" and other hybrid hadron-quark structure and our topology-change strategy represent the "hadron-quark duality" formulated in terms of the Cheshire-Cat mechanism~\cite{CC} for the smooth cross-over between hadrons and quarks. Confrontation with currently available experimental observations is discussed to support this notion.

    Comments:
    12 pages, 6 figures. title changed, notion of "Cheshire-Catism" sharpened. arXiv admin note: text overlap with arXiv:2101.07121
    Subjects:
    Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2104.13822 [pdf]
    14 citations
  3. 03

    [Submitted on 27 Apr 2021] (cross-list from hep-ph)

    Elastic photon-initiated production at the LHC: the role of hadron-hadron interactions

    L.A. Harland-Lang🇬🇧 · V.A. Khoze🇬🇧 · M.G. Ryskin🇷🇺

    We analyse in detail the role of additional hadron-hadron interactions in elastic photon-initiated (PI) production at the LHC, both in and heavy ion collisions. We first demonstrate that the source of difference between our predictions and other results in the literature for PI muon pair production is dominantly due to an unphysical cut that is imposed in these latter results on the dimuon-hadron impact parameter. We in addition show that this is experimentally disfavoured by the shape of the muon kinematic distributions measured by ATLAS in ultraperipheral PbPb collisions. We then consider the theoretical uncertainty due to the survival probability for no additional hadron-hadron interactions, and in particular the role this may play in the tendency for the predicted cross sections to lie somewhat above ATLAS data on PI muon pair production, in both and PbPb collisions. This difference is relatively mild, at the level, and hence a very good control over the theory is clearly required. We show that this uncertainty is very small, and it is only by taking very extreme and rather unphysical variations in the modelling of the survival factor that this tension can be removed. This underlines the basic, rather model independent, point that a significant fraction of elastic PI scattering occurs for hadron-hadron impact parameters that are simply outside the range of QCD interactions, and hence this sets a lower bound on the survival factor in any physically reasonable approach. Finally, other possible origins for this discrepancy are discussed.

    Comments:
    20 pages, 4 figures. Published version, some minor changes made
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2104.13392 [pdf]
    SciPost Phys.(2021)·40 citations
  4. 04

    [Submitted on 27 Apr 2021] (cross-list from hep-th)

    Spectral representation of the shear viscosity for local scalar QFTs at finite temperature

    Peter Lowdon🇩🇪 · Ralf-Arno Tripolt🇦🇹 · Jan M. Pawlowski🇩🇪 · Dirk H. Rischke🇩🇪

    In local scalar quantum field theories (QFTs) at finite temperature correlation functions are known to satisfy certain non-perturbative constraints, which for two-point functions in particular implies the existence of a generalisation of the standard Källén-Lehmann representation. In this work, we use these constraints in order to derive a spectral representation for the shear viscosity arising from the thermal asymptotic states, . As an example, we calculate in theory, establishing its leading behaviour in the small and large coupling regimes.

    Comments:
    21 pages, 3 figures; v3: additional references added as well as some minor text changes, matches published version
    Subjects:
    High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2104.13413 [pdf]
    PRD(2021)·12 citations
  5. 05

    [Submitted on 27 Apr 2021] (cross-list from hep-ph)

    Radial oscillations in neutron stars from QCD

    José C. Jiménez🇧🇷 · Eduardo S. Fraga🇧🇷

    We study the stability against infinitesimal radial oscillations of neutron stars generated by a set of equations of state obtained from first-principle calculations in cold and dense QCD and constrained by observational data. We consider mild and large violations of the conformal bound, , in stars that can possibly contain a quark matter core. Some neutron star families in the mass-radius diagram become dynamically unstable due to large oscillation amplitudes near the core.

    Comments:
    8 pages, 5 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
    arXiv:
    2104.13480 [pdf]
    PRD(2021)·15 citations
  6. 06

    [Submitted on 28 Apr 2021] (cross-list from astro-ph.HE)

    Impact of massive neutron star radii on the nature of phase transitions in dense matter

    Rahul Somasundaram🇫🇷 · Jérôme Margueron🇫🇷

    The last few years have seen tremendous progress in the observation of the global properties of neutron stars (NSs), e.g. masses, radii and tidal deformabilities. Such properties provide information about possible phase transitions in the inner cores of NSs, provided the connection between observed masses and radii and the equation of state (EoS) is well understood. We focus the present study on first-order phase transitions, which often softens the EoS and consequently reduces the maximum mass as well as the radii of NSs. Here, we challenge this conventional expectation by constructing explicit examples of EoSs undergoing a first-order phase transition, but which are much stiffer that their purely hadronic counterparts. We also provide comparisons with the recently proposed quarkyonic EoS which suggests a strong repulsion in the core of NSs, and we show that their stiffness can be realistically masqueraded by first-order phase transitions to exotic matter.

    Comments:
    7 pages, 4 figures
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    2104.13612 [pdf]
    EPL(2022)·41 citations
  7. 07

    [Submitted on 28 Apr 2021] (cross-list from nucl-ex)

    Investigating neutron transfer in the Be + Au system

    Malika Kaushik🇮🇳 · S.K. Pandit🇮🇳 · V.V. Parkar🇮🇳 · G. Gupta🇮🇳 · Swati Thakur🇮🇳 · V. Nanal🇮🇳 · H. Krishnamoorthy🇮🇳 · A. Shrivastava🇮🇳 · C.S. Palshetkar🇮🇳 · K. Mahata🇮🇳 · K. Ramachandran🇮🇳 · S. Pal🇮🇳 · R.G. Pillay🇮🇳 · Pushpendra P. Singh🇮🇳

    In this work -transfer and incomplete fusion cross sections for Be + Au system are reported over a wide energy range, E 29-45 MeV. The experiment was carried out using activation technique and off-line gamma counting. The transfer process is found to be the dominant mode as compared to all other reaction channels. Detailed coupled reaction channel (CRC) calculations have been performed for -transfer stripping and pickup cross sections. The measured 1-stripping cross sections are explained with CRC calculations by including the ground state and the 2 resonance state (E = 3.03 MeV) of Be. The calculations for 1-pickup, including only the ground state of Be agree reasonably well with the measured cross sections, while it overpredicts the data at subbarrier energies. For a better insight into the role of projectile structure in the transfer process, a comprehensive analysis of 1-stripping reaction has been carried out for various weakly bound projectiles on Au target nucleus. The transfer cross sections scaled with the square of total radius of interacting nuclei show the expected Q-value dependence of 1-stripping channel for weakly bound stable projectiles.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2104.13689 [pdf]
    PRC(2021)·23 citations

Affiliations

first authorsco-authorsvia INSPIRE