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Nuclear Theory·nucl-th

Tuesday·August 1, 2023

17 papers—7 primary·10 cross-listed

All17Primary7Cross-lists10
  1. 01

    [Submitted on 28 Jul 2023]

    Meson-exchange currents in quasielastic electron scattering in a generalized superscaling approach

    Paloma R. Casale🇪🇸 · J.E. Amaro🇪🇸 · M.B. Barbaro🇮🇹

    We present a model that incorporates the effect of two-body currents in quasielastic electron-nucleus scattering within the framework of a consistent superscaling formalism. This is achieved by defining an averaged single-nucleon hadronic tensor based on the 1p1h matrix element of the one-body current plus meson-exchange currents (MEC). The consistent treatment of one- and two-body currents in our model enables the calculation of exchange current effects in the kinematical region where the Fermi gas response is zero, but not the scaling function. The effect of MEC is consistently taken into account when extracting the phenomenological scaling function from electron scattering data. With this model, we investigate the effect of MEC on the response functions taking into account the effective mass of the nucleon, and examine the consequences it has on the inclusive cross section. We find that 1p1h MEC deplete the quasielastic transverse response, while they not alter significantly the scaling behavior of (e,e') data.

    Comments:
    20 pages, 16 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2307.15783 [pdf]
    Symmetry(2023)·10 citations
  2. 02

    [Submitted on 28 Jul 2023]

    Comment on "Electromagnetic form factors for nucleons in short-range correlations": arXiv:2305.13666

    Dmitry N. Kim (1) · Or Hen (2) · Gerald A. Miller (1) · E. Piasetzky (3) · M. Strikman (4) · L. Weinstein (5) ((1) Department of Physics, University of Washington, Seattle, WA 98195-1560, USA (2) Department of Physics, Massachusetts Institute of Technology, Cambridge Massachusetts 02139, USA (3) School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel (4) Department of Physics, The Pennsylvania State University, Norfolk, Virginia, 23529, USA (5) Department of Physics, Old Dominion University, Norfolk, Virginia, 23529, USA)

    The relationship between medium modifications of nuclear quark structure functions and medium modifications of elastic electromagnetic form factors is shown to be model dependent.

    Comments:
    2 pages, 1 figure
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2307.15821 [pdf]
    1 citation
  3. 03

    [Submitted on 29 Jul 2023]

    Spin-Induced Interactions and Heavy-Quark Transport in the QGP

    Zhanduo Tang🇺🇸 · Ralf Rapp🇺🇸

    A previously constructed -matrix approach for studying the quark-gluon plasma (QGP) is improved by incorporating spin-dependent interactions between partons. These interactions arise from the relativistic corrections to the Cornell potential. We first study the vacuum spectroscopy of quarkonia with this potential and find that a significant admixture of a vector component in the confining potential (rather than the previously considered scalar interaction) improves the description of the experimental mass splittings in - and -wave states. The in-medium potential containing the vector component in the confining interaction is constrained by fitting lattice-QCD results for heavy-quark (HQ) free energies and the equation of state (EoS) computed within in the selfconsistent -matrix framework. We subsequently extract the transport coefficients for charm quarks in the QGP with the improved in-medium potentials. The relativistic corrections to the vector component of the confining potential cause a notable increase in the thermal relaxation rate of charm quarks in the QGP in comparison to previous calculations, especially at high momenta. These results are expected to have significant ramifications for the phenomenology of open heavy-flavor observables at RHIC and the LHC.

    Comments:
    6 pages, 5 figures, Hard Probe 2023
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2307.16070 [pdf]
    PoS(2024)·1 citation
  4. 04

    [Submitted on 30 Jul 2023]

    Testing the validity of the surface approximation for reactions induced by weakly bound nuclei with a fully quantum-mechanical model

    Junzhe Liu · Jin Lei · Zhongzhou Ren

    We examine the validity of surface approximation for breakup reactions using a fully quantum-mechanical model proposed by Ichimura, Austern, and Vincent (IAV). Analogous to the semi-classical picture, we introduce radial cut-offs to scattering waves in the IAV framework, which we refer to as IAV-cut. Systematic calculations are conducted for nonelastic breakup reactions induced by Li and deuterons at various incident energies. A comparison between the results obtained from IAV and IAV-cut is performed. The excellent agreement observed between IAV and IAV-cut in Li induced reactions, regardless of incident energy and target nuclei, signifies their insensitivity to the inner part of the scattering wave function, thus providing validation for the semi-classical picture. However, for deuteron induced breakup reactions, the IAV-cut results exhibit a suppression in the cross section, suggesting a strong dependence on the interior wave functions. This suppression is further enhanced as the incident energy increases.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2307.16154 [pdf]
    PRC(2023)·5 citations
  5. 05

    [Submitted on 31 Jul 2023]

    Hybrid star structure from perturbative QCD

    Joydev Lahiri🇮🇳 · D. N. Basu🇮🇳

    The stellar configurations of quark stars are studied using perturbative QCD (pQCD) for the equation of state (EoS). The neutron star structures with equation of state obtained from Brussels-Montreal extended Skyrme interaction are also explored. The deconfinement phase transition from quark to hadron phase in stellar interior for matter under extreme pressure is accomplished by employing the Maxwell construction. The influence of hybrid EoS on the jump in energy density has been investigated. To study hybrid stars the BSk24 hadronic model and pQCD EoS for the quark phase have been used. The properties of hybrid stars in the view of the very recent astrophysical observations have been examined. We find that the gravitational mass might exceed 2.3 in some cases, comparable with the observed mass of the pulsar PSR J0952-0607 recently detected.

    Comments:
    6 pages including 4 figures and 1 table. arXiv admin note: text overlap with arXiv:2207.13384
    Subjects:
    Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR)
    arXiv:
    2307.16455 [pdf]
    0 citations
  6. 06

    [Submitted on 31 Jul 2023]

    Multi-particle correlations, cumulants, and moments sensitive to fluctuations in rare-probe azimuthal anisotropy in heavy ion collisions

    Abraham Holtermann🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Anne M. Sickles🇺🇸 · Xiaoning Wang🇺🇸

    Correlations of two or more particles have been an essential tool for understanding the hydrodynamic behavior of the quark-gluon plasma created in ultra-relativistic nuclear collisions. In this paper, we extend that framework to introduce a mathematical construction of multi-particle correlators that utilize correlations between arbitrary numbers of particles of interest (e.g. particles selected for their strangeness, heavy flavor, and conserved charges) and inclusive reference particles to estimate the azimuthal anisotropies of rare probes. To estimate the fluctuations and correlations in the azimuthal anisotropies of these particle of interest, we use these correlators in a system of cumulants, raw moments, and central moments. We finally introduce two classes of observables that can compare the fluctuations in the azimuthal anisotropies of particles of interest with reference particles at each order.

    Comments:
    29 pages, 1 figure, 2 tables
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2307.16796 [pdf]
    PRC(2023)·14 citations
  7. 07

    [Submitted on 28 Jul 2023]

    Predicted Measurements of the Tensor-to-Scalar Transition in the CLAS12 Nuclear Targets Experiment

    Erin Marshall Seroka🇺🇸 · Axel Schmidt🇺🇸

    Short-range correlated (SRC) nucleon pairs, which are strongly interacting nucleons at short inter-particle distances, can reveal properties of the effective nucleon-nucleon (\textit{NN}) interaction at short distance scales. The relative abundance of proton-proton (\textit{pp}) pairs and proton-neutron (\textit{pn}) pairs, for example, is sensitive to the tensor contribution to the \textit{NN} interaction. Generalized Contact Formalism (GCF) theory, when used with realistic phenomenological \textit{NN} potential models, predicts a transition from a tensor-dominated regime -- at relative momenta of approximately 400~MeV/\textit{c} where \textit{pp} pairs are suppressed relative to \textit{pn} pairs -- to a scalar-dominated regime at higher momenta with no preferred isospin projection. While an increase in the prevalence of \textit{pp} pairs with increasing momentum has been observed in a few experiments, difficulties associated with neutron detection have so far hindered the observation of a corresponding reduction in the abundance of \textit{pn} pairs. High-precision measurements showing a simultaneous increase in the abundance of \textit{pp} pairs and change in the abundance of \textit{pn} pairs with increasing momentum would conclusively demonstrate the existence of the tensor-to-scalar transition. In this work, we study the potential impact of the recently conducted Nuclear Targets Experiment at the CLAS12 detector at Jefferson Lab, using GCF simulations. We model the expected yields and relevant observables for a carbon target with a beam energy of 6 GeV and show that sufficient statistical precision can be obtained from the experimental data, both for \textit{pp} and \textit{pn} pairs, to observe the tensor-to-scalar transition.

    Comments:
    23 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2307.16818 [pdf]
    EPJA(2023)·1 citation
  8. 08

    [Submitted on 28 Jul 2023] (cross-list from hep-ph)

    Energy Correlators on Tracks: Resummation and Non-Perturbative Effects

    Max Jaarsma🇳🇱 · Yibei Li🇨🇳 · Ian Moult🇺🇸 · Wouter J. Waalewijn🇳🇱 · Hua Xing Zhu🇨🇳

    Energy correlators measured inside high-energy jets at hadron colliders have recently been demonstrated to provide a new window into both perturbative and non-perturbative Quantum Chromodynamics. A number of the most interesting features of these correlators, namely their universal scaling behavior and the ability to image the confinement transition, require precise angular resolution, necessitating the use of tracking information in experimental measurements. Theoretically, tracking information can be incorporated into the energy correlators using track functions, which are non-perturbative functions describing the fragmentation of quarks and gluons into charged hadrons. In this paper, we apply our recently developed track function formalism to energy correlators, and study in detail the interplay of track functions with perturbative resummation and non-perturbative power corrections. We provide resummed results for the energy correlators at collinear next-to-leading-logarithmic accuracy and compare with parton shower Monte Carlo simulations. For the two-point correlator the use of tracking has a minimal effect throughout the entire distribution, but it has a significant effect for higher point correlators. Our results are crucial for the theoretical interpretation of recent experimental measurements of the energy-energy correlators.

    Comments:
    26 pages, 10 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2307.15739 [pdf]
    JHEP(2023)·64 citations
  9. 09

    [Submitted on 28 Jul 2023] (cross-list from hep-th)

    Chiral effects: new trends

    G. Yu. Prokhorov🇷🇺 · O. V. Teryaev🇷🇺 · V. I. Zakharov🇷🇺

    By chiral effects one understands manifestations of chiral gauge anomaly and of gravitational chiral anomaly in hydrodynamics. In recent two-three years our understanding of the chiral effects has considerably changed. Here we present mini-review of two topics. First, shift in understanding symmetry which underlies the chiral magnetic effect and, second, interpretation of the chiral kinematical effect uncovered recently.

    Comments:
    Contribution to: Infinite and Finite Nuclear Matter (INFINUM-2023)
    Subjects:
    High Energy Physics — Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2307.15757 [pdf]
    0 citations
  10. 10

    [Submitted on 30 Jul 2023] (cross-list from hep-ph)

    Bremsstrahlung Cross Section with Polarized Beams for Luminosity Determination at the EIC

    Dhevan Gangadharan🇺🇸

    The bremsstrahlung cross section is calculated at leading order for polarized beams of electrons and ions, which is needed for luminosity measurements at the upcoming Electron Ion Collider (EIC). Analytic expressions, differential in the emitted photon energy and polar angle, are derived. The component of the cross section which depends on the beam polarizations is found to be highly suppressed with respect to the unpolarized Bethe-Heitler component, owing to the low that characterizes the bremsstrahlung process.

    Comments:
    5 pages, 3 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2307.16245 [pdf]
    EPJA(2023)·1 citation
  11. 11

    [Submitted on 30 Jul 2023] (cross-list from hep-ph)

    Classical vs. quantum corrections to jet broadening in a weakly coupled QGP

    Eamonn Weitz🇫🇷

    We compute double-logarithmically enhanced corrections to at relative order in the setting of a weakly coupled quark-gluon plasma, observing how the thermal scale affects the region of phase space, which gives rise to these corrections. We furthermore clarify how the region of phase from which these corrections are borne is situated with respect to that from which the classical corrections arise at relative order . This represents a significant step towards our eventual goal of understanding which class of corrections dominate, thereby pushing forward our quantitative grasp on the phenomenon of jet quenching in heavy-ion collisions.

    Comments:
    6 pages, 2 figures, to appear in proceedings for Hard Probes 2023
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2307.16250 [pdf]
    PoS(2024)·0 citations
  12. 12

    [Submitted on 30 Jul 2023] (cross-list from nucl-ex)

    Precise determination of Pb Decay Spectrum at 0 keV and its Implication to Theoretical Calculations

    Shuo Zhang🇨🇳 · Xavier Mougeot🇫🇷 · Hao-Ran Liu🇨🇳 · Ke Han🇨🇳 · Tao Sun🇨🇳 · Wen-Tao Wu🇨🇳 · Robin Cantor🇺🇸 · Jing-Kai Xia🇨🇳 · Jun-Cheng Liang🇨🇳 · Fu-You Fan🇨🇳 · Bing-Jun Wu🇨🇳 · Le Zhang🇨🇳 and 3 other authors

    The atomic exchange effect will lead to a significant increase in the probability density of decays below a few keV. This effect is very important for scientific experiments that performed by low-energy electron spectroscopy measurements. However, the atomic exchange effect involves multi-electron interactions, especially for a system with 82 electrons such as lead. Different parameters will lead to different trends in the energy spectrum predicted by the theory, so it is urgent to carry out experimental measurements to provide parameter limits for the theory. The probability increase brought about by the atomic exchange effect is most obvious near 0keV, and the energy spectrum is accurately measured near this energy point, so as to provide constraints for the physical model of atomic exchange. However, it is extremely difficult to measure the energy spectrum at 0keV due to the limitations of electronic noise and internal conversion effects. The excited decay path of Pb was taken as the observation object,by measuring the total energy spectrum of rays and cascaded gamma rays, the precise measurement of the energy spectrum near 0keV has been completed. The analysis of the energy spectrum of Pb gives the following conclusions. The experimental results first verified the theory that the exchange effect causes the probability increase at the low energy end near 0keV. At the same time, the experimental results are higher than the existing predictions of the atomic exchange effect. At least for Pb element, all the electron shells have played a role in improving the probability density of the low end of the energy spectrum. This discovery will promote the theoretical calculation of the energy spectrum of Pb, at the same time, it also indicates that the reactor neutrinos have a higher probability density at the omnipotent end.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2307.16276 [pdf]
    2 citations
  13. 13

    [Submitted on 30 Jul 2023] (cross-list from hep-ph)

    Hadronic structure on the light-front VIII. Light scalar and vector mesons

    Wei-Yang Liu🇺🇸 · Edward Shuryak🇺🇸 · Ismail Zahed🇺🇸

    We use the QCD instanton vacuum model to discuss the emergence of the light scalar and vector mesons on the light front. We take into account both the instanton and anti-instanton single and molecular interactions on the light quarks, in the form of non-local effective interactions. Although the molecular induced interactions are suppressed by a power of the packing fraction, they are still sufficient to bind the vector mesons, while keeping most of the scalar spectrum relatively unchanged. We explicitly derive the light front distribution amplitudes (DAs) and partonic functions (PDFs) for the scalar and vector mesons, and compare them after pertinent QCD evolution, to the available empirical and lattice measured counterparts. The Dirac electric form factors for both the pion and rho meson are derived, and shown to compare well with current data.

    Comments:
    42 pages, 24 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2307.16302 [pdf]
    PRD(2024)·19 citations
  14. 14

    [Submitted on 31 Jul 2023] (cross-list from hep-th)

    Numerical analysis of a baryon and its dilatation modes in holographic QCD

    Keiichiro Hori (Kyoto U.)🇯🇵 · Hideo Suganuma (Kyoto U.)🇯🇵 · Hiroki Kanda (YITP, Kyoto U.)🇯🇵

    We investigate a baryon and its dilatation modes in holographic QCD based on the Sakai-Sugimoto model, which is expressed as a 1+4 dimensional U() gauge theory in the flavor space. For spatially rotational symmetric systems, we apply a generalized version of the Witten Ansatz, and reduce 1+4 dimensional holographic QCD into a 1+2 dimensional Abelian Higgs theory in a curved space. In the reduced theory, the holographic baryon is described as a two-dimensional topological object of an Abrikosov vortex. We numerically calculate the baryon solution of holographic QCD using a fine and large lattice with spacing of 0.04 fm and size of 10 fm. Using the relation between the baryon size and the zero-point location of the Higgs field in the description with the Witten Ansatz, we investigate a various-size baryon through this vortex description. As time-dependent size-oscillation modes (dilatation modes) of a baryon, we numerically obtain the lowest excitation energy of 577 MeV and deduce the dilatational excitation of a nucleon to be the Roper resonance N(1440).

    Comments:
    22 pages, 14 figures
    Subjects:
    High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2307.16590 [pdf]
    PRD(2024)·3 citations
  15. 15

    [Submitted on 31 Jul 2023] (cross-list from hep-ph)

    Quantum local-equilibrium state with fixed multiplicity constraint and Bose-Einstein momentum correlations

    M.D. Adzhymambetov🇺🇦 · S.V. Akkelin🇺🇦 · Yu.M. Sinyukov🇺🇦

    The one- and two-boson momentum spectra are derived in the quantum local-equilibrium canonical ensemble of noninteracting bosons with a fixed particle number constraint. We define the canonical ensemble as a subensemble of events associated with the grand-canonical ensemble. Applying simple hydro-inspired parametrization with parameter values that correspond roughly to the values at the system's breakup in collisions at the LHC energies, we compare our findings with the treatment which is based on the grand-canonical ensembles where mean particle numbers coincide with fixed particle numbers in the canonical ensembles. We observe a significantly greater sensitivity of the two-particle momentum correlation functions to fixed multiplicity constraint compared to one-particle momentum spectra. The results of our analysis may be useful for interpretation of multiplicity-dependent measurements of collision events.

    Comments:
    27 pages, 8 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2307.16633 [pdf]
    PRD(2023)·3 citations
  16. 16

    [Submitted on 31 Jul 2023] (cross-list from hep-ph)

    Equilibration of quantum many-body fast neutrino flavor oscillations

    Joshua D. Martin🇺🇸 · Duff Neill🇺🇸 · A. Roggero🇮🇹 · Huaiyu Duan🇺🇸 · J. Carlson🇺🇸

    Neutrino gases are expected to form in high density astrophysical environments, and accurately modeling their flavor evolution is critical to understanding such environments. In this work we study a simplified model of such a dense neutrino gas in the regime for which neutrino-neutrino coherent forward scattering is the dominant mechanism contributing to the flavor evolution. We show evidence that the generic potential induced by this effect is non-integrable and that the statistics of its energy level spaces are in good agreement with the Wigner surmise. We also find that individual neutrinos rapidly entangle with all of the others present which results in an equilibration of the flavor content of individual neutrinos. We show that the average neutrino flavor content can be predicted utilizing a thermodynamic partition function. A random phase approximation to the evolution gives a simple picture of this equilibration. In the case of neutrinos and antineutrinos, processes like yield a rapid equilibrium satisfying in addition to the standard lepton number conservation in regimes where off-diagonal vacuum oscillations are small compared to interactions.

    Comments:
    16 pages, 8 figures, 1 appendix
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2307.16793 [pdf]
    PRD(2023)·49 citations
  17. 17

    [Submitted on 31 Jul 2023] (cross-list from hep-ph)

    Impact of NNLO QED corrections on lepton-proton scattering at MUSE

    T. Engel🇩🇪 · F. Hagelstein🇩🇪 · M. Rocco🇨🇭 · V. Sharkovska🇨🇭 · A. Signer🇨🇭 · Y. Ulrich🇬🇧

    We present the complete next-to-next-to-leading order (NNLO) pure pointlike QED corrections to lepton-proton scattering, including three-photon-exchange contributions, and investigate their impact in the case of the MUSE experiment. These corrections are computed with no approximation regarding the energy of the emitted photons and taking into account lepton-mass effects. We contrast the NNLO QED corrections to known next-to-leading order corrections, where we include the elastic two-photon exchange (TPE) through a simple hadronic model calculation with a dipole ansatz for the proton electromagnetic form factors. We show that, in the low-momentum-transfer region accessed by the MUSE experiment, the improvement due to more sophisticated treatments of the TPE, including inelastic TPE, is of similar if not smaller size than some of the NNLO QED corrections. Hence, the latter have to be included in a precision determination of the low-energy proton structure from scattering data, in particular for electron-proton scattering. For muon-proton scattering, the NNLO QED corrections are considerably smaller.

    Comments:
    Article to be submitted to the EPJ A Topical Collection: Radiative Corrections: From Medium to High Energy Experiments. 23 pages, 9 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2307.16831 [pdf]
    EPJA(2023)·15 citations

Affiliations

first authorsco-authorsvia INSPIRE