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Nuclear Theory·nucl-th

Wednesday·July 26, 2023

14 papers—8 primary·6 cross-listed

All14Primary8Cross-lists6
  1. 09

    [Submitted on 24 Jul 2023] (cross-list from math.NA)

    Constraining neutron star properties and dark matter admixture with the NITR-I equation of state: Insights from observations and universal relations

    Pinku Routaray · H C Das · Jeet Amrit Pattnaik · Bharat Kumar

    A recent observational study has constrained the maximum mass of neutron stars (NSs), with particular attention to PSR J0952-0607 and the compact star remnant HESS J1731-347, especially in the low-mass regime. Building on our earlier work, which developed the NITR energy density functional (EDF) to reproduce the mass limit of PSR J0952-0607 but did not satisfy other observational constraints, this study introduces a refined EDF named ``NITR-I". NITR-I successfully reconciles the PSR J0952-0607 mass limit with observational data, including radius measurements from NICER+XMM and tidal deformability constraints from GW170817, demonstrating its robustness. The low-mass constraint associated with HESS J1731-347 indicates diverse NS compositions. Since NITR-I alone cannot satisfy this constraint, we explore the role of dark matter (DM) within NSs to bridge the gap. Incorporating DM, particularly at specific Fermi momentum values, enables the model to address this constraint. We further analyze the influence of DM on various NS properties, such as tidal deformability and non-radial -mode oscillations, across multiple relativistic mean-field models. The presence of DM suggests a reduction in tidal deformability and shifts in oscillation frequencies, potentially offering detectable signatures in gravitational wave observations from neutron star mergers. Additionally, we investigate universal relations (URs) for DM-admixed NSs, focusing on correlations such as compactness versus tidal deformability and -mode frequency versus tidal deformability. Canonical values for these properties are estimated using GW170817 data, offering further insights into the structure and composition of neutron stars.

    Comments:
    Published in IJMPE
    Subjects:
    math.NA (math.NA); High Energy Astrophysical Phenomena (astro-ph.HE); cs.NA (cs.NA); Nuclear Theory (nucl-th)
    arXiv:
    2307.12748 [pdf]
    IJMPE(2024)·17 citations
  2. 10

    [Submitted on 24 Jul 2023] (cross-list from hep-ph)

    Transverse Momentum Measurements with Jets at Next-to-Leading Power

    Rafael F. del Castillo🇪🇸 · Max Jaarsma🇳🇱 · Ignazio Scimemi🇪🇸 · Wouter Waalewijn🇳🇱

    In view of the increasing precision of theoretical calculations and experimental measurements, power corrections to transverse-momentum-dependent observables are highly important. We study the next-to-leading power corrections for transverse momentum measurements in jets. We obtain a factorized expression for the cross section, which involve twist-2 and twist-3 operators, and identify the new jet functions that appear in it. We calculate these jet functions at order {\alpha}s for a family of recoil-free schemes, and provide the corresponding anomalous dimensions at leading order. Additionally, we show that the (endpoint) divergences that typically arise in sub-leading-power factorization can be subtracted and cancel for our case. By working with jets, everything is perturbatively calculable and there are substantial simplifications compared to the general next-to-leading power framework. Importantly, our analysis with jets can be extended to semi-inclusive deep-inelastic scattering, with the future Electron-Ion Collider as key application.

    Comments:
    30 pages, 4 figures, v3: journal version
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2307.13025 [pdf]
    JHEP(2024)·10 citations
  3. 11

    [Submitted on 24 Jul 2023] (cross-list from hep-ph)

    ALP contributions to conversion

    Kaori Fuyuto🇺🇸 · Emanuele Mereghetti🇺🇸

    We study the conversion process in nuclear targets arising in models of axion-like particles (ALPs) with hadronic and charged lepton flavor violating (CLFV) interactions. Contributions to this process generally fall into two categories: spin-independent (SI) and spin-dependent (SD). While the SI contribution can be generated by a dipole operator through purely leptonic ALP interactions, the SD contribution can also be present through ALP-quark interactions at tree-level. It is naively anticipated that the SI contribution would be dominant due to its coherent enhancement. In this , we show that is not generically the case; in particular, for naturally-sized ALP couplings to quarks of order , the SD interaction induced by ALP- mixing turns out to be the leading contribution to conversion. Intuitively, this stems from the suppressed dipole contribution by the QED one-loop factor which counters the effect of SI coherent enhancement. Our study highlights the importance of conversion searches in exploring the parameter space of generic ALP models, and demonstrates the competitiveness of these searches in probing the CLFV ALP parameter space in the heavy mass range of .

    Comments:
    6 pages, 4 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2307.13076 [pdf]
    5 citations
  4. 12

    [Submitted on 25 Jul 2023] (cross-list from hep-lat)

    Lattice QCD study of scattering and the resonance

    John Bulava🇩🇪 · Bárbara Cid-Mora🇩🇪 · Andrew D. Hanlon🇺🇸 · Ben Hörz🇩🇪 · Daniel Mohler🇩🇪 · Colin Morningstar🇺🇸 · Joseph Moscoso🇺🇸 · Amy Nicholson🇺🇸 · Fernando Romero-López🇺🇸 · Sarah Skinner🇺🇸 · André Walker-Loud🇺🇸

    A lattice QCD computation of the coupled channel scattering amplitudes in the region is detailed. Results are obtained using a single ensemble of gauge field configurations with dynamical quark flavors and MeV and MeV. Hermitian correlation matrices using both single baryon and meson-baryon interpolating operators for a variety of different total momenta and irreducible representations are used. Several parametrizations of the two-channel scattering -matrix are utilized to obtain the scattering amplitudes from the finite-volume spectrum. The amplitudes, continued to the complex energy plane, exhibit a virtual bound state below the threshold and a resonance pole just below the threshold.

    Comments:
    18 pages, 11 figures, 14 tables. Final version accepted for publication in PRD with post-publication corrections
    Subjects:
    High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2307.13471 [pdf]
    PRD(2024)·71 citations
  5. 13

    [Submitted on 25 Jul 2023] (cross-list from hep-ph)

    Scalar propagator in a background gluon field beyond the eikonal approximation

    Pedro Agostini🇪🇸

    We investigate the path integral representation of the scalar propagator in a background gluon field, extending beyond the eikonal approximation by considering all gauge field components and incorporating its dependence. Utilizing the worldline formalism, we integrate the Schwinger proper time to express the scalar propagator in light-cone coordinates, facilitating a direct comparison with known results in the literature. The derived propagator captures the change of longitudinal momentum of the projectile within the medium. In the high-energy limit, our result simplifies to the effective gluon propagator employed in the BDMPS-Z formalism. Hence, we propose that our outcome serves as a foundational point for investigating corrections to the BDMPS-Z spectrum arising from the longitudinal momentum transfer of the radiated gluon with the medium, as well as for studying collisional energy loss phenomena. Lastly, by employing an expansion around the classical saddle point solution, we systematically derive an eikonal expansion in inverse powers of the boost parameter, encompassing corrections related to longitudinal momentum transfer and interactions of the projectile with the transverse component of the field.

    Comments:
    47 pages, 4 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2307.13573 [pdf]
    JHEP(2023)·11 citations
  6. 14

    [Submitted on 25 Jul 2023] (cross-list from hep-ph)

    Order parameters for gauge invariant condensation far from equilibrium

    Jürgen Berges🇩🇪 · Kirill Boguslavski🇦🇹 · Lillian de Bruin🇩🇪 · Tara Butler🇩🇪 · Jan M. Pawlowski🇩🇪

    Nuclear collisions at sufficiently high energies are expected to produce far-from-equilibrium matter with a high density of gluons at early times. We show gauge condensation, which occurs as a consequence of the large density of gluons. To identify this condensation phenomenon, we construct two local gauge-invariant observables that carry the macroscopic zero mode of the gauge condensate. The first order parameter for gauge condensation investigated here is the correlator of the spatial Polyakov loop. We also consider, for the first time, the correlator of the gauge invariant scalar field, associated to the exponent of the Polyakov loop. Using real-time lattice simulations of classical-statistical gauge theory, we find gauge condensation on a system-size dependent time scale with a universal scaling exponent . Furthermore, we suggest an effective theory formulation describing the dynamics using one of the order parameters identified. The formation of a condensate at early times may have intriguing implications for the early stages in heavy ion collisions.

    Comments:
    11 pages, 9 figures, 1 table
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Quantum Gases (cond-mat.quant-gas); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2307.13669 [pdf]
    PRD(2024)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE