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Nuclear Theory·nucl-th

Thursday·February 27, 2020

7 papers—2 primary·5 cross-listed

All7Primary2Cross-lists5
  1. 01

    [Submitted on 25 Feb 2020]

    Finite-Temperature Quarkyonic Matter with an Excluded Volume Model

    Srimoyee Sen🇺🇸 · Neill C. Warrington🇺🇸

    We introduce a theoretical framework to analyze the thermal properties of a recently proposed "excluded volume" model of quarkyonic matter. This entails proposing finite temperature distribution functions and entropy functionals constrained by internal theoretical consistency. We use the formalism developed here to analyze the effect of temperature on the quark onset as a function of baryon density. We find that the baryon density at which the quarkyonic phase emerges decreases only slightly with temperature, an effect produced by large . We furthermore find that a finite temperature increases the density of quarks produced. The framework presented here can be used to compute the equation of state of hot and dense quarkyonic matter which is of relevance to neutron star mergers.

    Comments:
    14 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2002.11133 [pdf]
    NPA(2021)·41 citations
  2. 02

    [Submitted on 26 Feb 2020]

    Higher-order cumulants of net-charge distributions from local charge conservation

    Igor Altsybeev🇷🇺

    In studies of heavy-ion collisions, fluctuations of conserved quantities are considered as an important signal of the transition between the hadronic and partonic phases of nuclear matter. In this paper, it is investigated how the local charge conservation affects higher-order cumulants of net-charge distributions at LHC energies. Simple expressions for the cumulants are derived under the assumption that particle-antiparticle pairs are produced in local processes from sources that are nearly uncorrelated in rapidity. For calculations with these expressions, one needs to know only the second cumulant of net-charge distribution and low-order cumulants of particle number distribution, which are directly measurable experimentally. It is argued that if one wishes to relate susceptibilities with cumulants of net-proton distributions, the developed model provides a better baseline than the conventional Skellam limit or models based on monte-carlo simulations.

    Comments:
    10 pages, 8 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex)
    arXiv:
    2002.11398 [pdf]
    PoS(2022)·4 citations
  3. 03

    [Submitted on 25 Feb 2020] (cross-list from quant-ph)

    Quantum Algorithms for Simulating the Lattice Schwinger Model

    Alexander F. Shaw🇺🇸 · Pavel Lougovski🇺🇸 · Jesse R. Stryker🇺🇸 · Nathan Wiebe🇺🇸

    The Schwinger model (quantum electrodynamics in 1+1 dimensions) is a testbed for the study of quantum gauge field theories. We give scalable, explicit digital quantum algorithms to simulate the lattice Schwinger model in both NISQ and fault-tolerant settings. In particular, we perform a tight analysis of low-order Trotter formula simulations of the Schwinger model, using recently derived commutator bounds, and give upper bounds on the resources needed for simulations in both scenarios. In lattice units, we find a Schwinger model on physical sites with coupling constant and electric field cutoff can be simulated on a quantum computer for time using a number of -gates or CNOTs in for fixed operator error. This scaling with the truncation is better than that expected from algorithms such as qubitization or QDRIFT. Furthermore, we give scalable measurement schemes and algorithms to estimate observables which we cost in both the NISQ and fault-tolerant settings by assuming a simple target observable---the mean pair density. Finally, we bound the root-mean-square error in estimating this observable via simulation as a function of the diamond distance between the ideal and actual CNOT channels. This work provides a rigorous analysis of simulating the Schwinger model, while also providing benchmarks against which subsequent simulation algorithms can be tested.

    Subjects:
    Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2002.11146 [pdf]
    Quantum(2020)·206 citations
  4. 04

    [Submitted on 26 Feb 2020] (cross-list from hep-ph)

    Heavy Quark Energy Loss in the Quark-Gluon Plasma in the Moller theory

    B. Blok (Technion)🇮🇱

    We study the energy loss of a heavy quark propagating in the Quark-Gluon Plasma (QGP) in the framework of the Moller theory, including possible large Coulomb logarithms as a perturbation to BDMPSZ bremsstrahlung, described in the Harmonic Oscillator (HO) approximation. We derive the analytical expression that describes the energy loss in the entire emitted gluon frequency region. In the small frequencies region, for angles larger than the dead cone angle, the energy loss is controlled by the BDMPSZ mechanism, while for larger frequencies it is described by N=1 term in the GLV opacity expansion. We estimate corresponding quenching rates for different values of the heavy quark path and different ratios.

    Comments:
    20 pages, 4 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2002.11233 [pdf]
    EPJC(2020)·5 citations
  5. 05

    [Submitted on 26 Feb 2020] (cross-list from astro-ph.HE)

    Chiral Radiation Transport Theory of Neutrinos

    Naoki Yamamoto🇯🇵 · Di-Lun Yang🇯🇵

    We construct the chiral radiation transport equation for left-handed neutrinos in the context of radiation hydrodynamics for core-collapse supernovae. Based on the chiral kinetic theory incorporating quantum corrections due to the chirality of fermions, we derive a general relativistic form of the chiral transfer equation with collisions. We show that such quantum corrections explicitly break the spherical symmetry and axisymmetry of the system. In the inertial frame, in particular, we find that the so-called side jump leads to quantum corrections in the collisions between neutrinos and matter. We also derive analytic forms of such corrections in the emission and absorption rates for the neutrino absorption process. These corrections result in the generation of kinetic helicity and cross helicity of matter, which should then modify the subsequent evolution of matter. This theoretical framework can be applied to investigate the impacts of the chirality of neutrinos on the evolution of core-collapse supernovae.

    Comments:
    21 pages, no figures, very minor revisions, journal version
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2002.11348 [pdf]
    ApJ(2020)·36 citations
  6. 06

    [Submitted on 26 Feb 2020] (cross-list from astro-ph.HE)

    Multi-messenger constraints on the neutron-star equation of state and the Hubble constant

    Tim Dietrich🇩🇪 · Michael W. Coughlin🇺🇸 · Peter T. H. Pang🇳🇱 · Mattia Bulla🇸🇪 · Jack Heinzel🇺🇸 · Lina Issa🇸🇪 · Ingo Tews🇺🇸 · Sarah Antier🇫🇷

    Observations of neutron-star mergers based on distinct messengers, including gravitational waves and electromagnetic signals, can be used to study the behavior of matter denser than an atomic nucleus, and to measure the expansion rate of the Universe described by the Hubble constant. We perform a joint analysis of the gravitational-wave signal GW170817 with its electromagnetic counterparts AT2017gfo and GRB170817A, and the gravitational-wave signal GW190425, both originating from neutron-star mergers. We combine these with previous measurements of pulsars using X-ray and radio observations, and nuclear-theory computations using chiral effective field theory to constrain the neutron-star equation of state. We find that the radius of a solar mass neutron star is at confidence and the Hubble constant is at uncertainty.

    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
    arXiv:
    2002.11355 [pdf]
    Science(2020)·512 citations
  7. 07

    [Submitted on 26 Feb 2020] (cross-list from nucl-ex)

    Measurement of the charge separation along the magnetic field with Signed Balance Function in 200 GeV Au + Au collisions at STAR

    Yufu Lin (for the STAR Collaboration)🇨🇳

    Experimental searches for Chiral Magnetic Effect (CME) in heavy-ion collisions have been going on for a decade, and so far there is no conclusive evidence for its existence. Recently, the Signed Balance Function (SBF), based on the idea of examining the momentum ordering of charged pairs along the in- and out-of-plane directions, has been proposed as a probe of CME. In this approach, a pair of observables is invoked: one is , the out-of-plane to in-plane ratio of measured in pair's rest frame, where is the difference between signed balance functions; The other is a double ratio, , where is a measurement similar to but measured in the laboratory frame. These two observables give opposite responses to the CME-driven charge separation compared to the background correlations arising from resonance flow and global spin alignment. Both and being larger than unity can be regarded as a case in favor of the existence of CME. It is found experimentally that , and are larger than unity in Au+Au collisions at 200 GeV, and larger than realistic model calculations with no CME implemented. These findings are difficult to be explained by a background-only scenario.

    Comments:
    4 pages, 6 figures, Proceedings of 28th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2019) A typo has been corrected
    Subjects:
    Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2002.11446 [pdf]
    NPA(2021)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE