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Nuclear Theory·nucl-th

Wednesday·September 11, 2019

8 papers—1 primary·7 cross-listed

All8Primary1Cross-lists7
  1. 02

    [Submitted on 9 Sept 2019] (cross-list from physics.data-an)

    A new Monte Carlo-based fitting method

    Paolo Pedroni (INFN, Pavia)🇮🇹 · Stefano Sconfietti (University and INFN, Pavia)🇮🇹

    We present a new fitting technique based on the parametric bootstrap method, which relies on the idea to produce artificial measurements using the estimated probability distribution of the experimental data. In order to investigate the main properties of this technique, we develop a toy model and we analyze several fitting conditions with a comparison of our results to the ones obtained using both the standard minimization procedure and a Bayesian approach. Furthermore, we investigate the effect of the data systematic uncertainties both on the probability distribution of the fit parameters and on the shape of the expected goodness-of-fit distribution. Our conclusion is that, when systematic uncertainties are included in the analysis, only the bootstrap procedure is able to provide reliable confidence intervals and p-values, thus improving the results given by the standard minimization approach. Our technique is then applied to an actual physics process, the real Compton scattering off the proton, thus confirming both the portability and the validity of the bootstrap-based fit method.

    Comments:
    27 pages, 20 figures, 7 tables; final version accepted for publication in J. Phys.G
    Subjects:
    Data Analysis, Statistics and Probability (physics.data-an); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1909.03885 [pdf]
    J.Phys.G(2020)·12 citations
  2. 03

    [Submitted on 9 Sept 2019] (cross-list from hep-th)

    The QCD Trace Anomaly at Strong Coupling from M-Theory

    Aalok Misra🇮🇳 · Charles Gale🇨🇦

    In this short note we address the issue of obtaining the temperature dependence of the QCD conformal anomaly from a top-down holographic dual consistent with very recent lattice results for both, T<Tc and T>Tc. As the holographic dual, we use the M-theory uplift of the SYZ type IIA mirror obtained in arXiv:1306.4339 at finite gauge/string coupling (as part of the 'MQGP' limit) of the type IIB holographic dual of large-N thermal QCD of arXiv:0902.1540. We also show that after a tuning of the (small) Ouyang embedding parameter and radius of a blown-up S^2 when expressed in terms of the horizon radius, a QCD deconfinement temperature Tc = 150 MeV from a Hawking-Page phase transition at vanishing baryon chemical potential, consistent with lattice QCD in the heavy-quark limit, can be obtained.

    Comments:
    v3: 27 pages, LaTeX; references, clarifying text and a table added; to appear in EPJC
    Subjects:
    High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1909.04062 [pdf]
    EPJC(2020)·20 citations
  3. 04

    [Submitted on 9 Sept 2019] (cross-list from astro-ph.HE)

    Searching for exotic cores with binary neutron star inspirals

    Hsin-Yu Chen🇺🇸 · Paul M. Chesler🇺🇸 · Abraham Loeb🇺🇸

    We study the feasibility of detecting exotic cores in merging neutron stars with ground-based gravitational-wave detectors. We focus on models with a sharp nuclear/exotic matter interface, and assume a uniform distribution of neutron stars in the mass range . We find that the existence of exotic cores can be confirmed at the 70% confidence level with as few as several tens of detections. Likewise, with such a sample, we find that some models of exotic cores can be excluded {with high confidence}.

    Comments:
    ApJL accepted version
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
    arXiv:
    1909.04096 [pdf]
    ApJL(2020)·21 citations
  4. 05

    [Submitted on 10 Sept 2019] (cross-list from hep-ph)

    Traces of the nuclear liquid-gas phase transition in the analytic properties of hot QCD

    Oleh Savchuk🇺🇦 · Volodymyr Vovchenko🇩🇪 · Roman V. Poberezhnyuk🇩🇪 · Mark I. Gorenstein🇩🇪 · Horst Stoecker🇩🇪

    The nuclear liquid-gas transition at normal nuclear densities, fm, and small temperatures, MeV, has a large influence on analytic properties of the QCD grand-canonical thermodynamic potential. A classical van der Waals equation is used to determine these unexpected features due to dense cold matter qualitatively. The existence of the nuclear matter critical point results in thermodynamic branch points, which are located at complex chemical potential values, for MeV, and exhibit a moderate model dependence up to rather large temperatures MeV. The behavior at higher temperatures is studied using the van der Waals hadron resonance gas (vdW-HRG) model. The baryon-baryon interactions have a decisive influence on the QCD thermodynamics close to . In particular, nuclear matter singularities limit the radius of convergence of the Taylor expansion in , with values at MeV obtained in the vdW-HRG model.

    Comments:
    11 pages, 5 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1909.04461 [pdf]
    PRC(2020)·25 citations
  5. 06

    [Submitted on 10 Sept 2019] (cross-list from astro-ph.HE)

    Re-visiting gravitational wave events via pulsars

    Minati Biswal🇮🇳 · Shreyansh S. Dave🇮🇳 · Ajit M. Srivastava🇮🇳

    By now many gravitational wave (GW) signals have been detected by LIGO and Virgo, with the waves reaching earth directly from their respective sources. These waves will also travel to different pulsars and will cause (tiny) transient deformations in the pulsar shape. Some of us have recently shown that the resultant transient change in the pulsar moment of inertia may leave an observable imprint on the pulsar signals as detected on earth, especially at resonance. The pulsars may thus act as remotely stationed Weber gravitational wave detectors. This allows us to revisit the past GW events via pulsars. We give here a list of specific pulsars whose future signals will carry the imprints of past GW events, to be specific we constrain it within 50 years. Some interesting cases are, supernova SN1987A with earliest perturbed signals from pulsars J0709-5923 and B0559-57 expected to reach earth in 2023 and 2024 respectively, Crab supernova, with perturbed signal arrival date from pulsar J1856-3754 in 2057, and GW170814 event with its imprints on the signals on the pulsar J0437-4715 reaching earth between 2035-2043. Even the earliest recorded supernova SN185 event may become observable again via pulsar J0900-3144 with the perturbed pulsar signal reaching us sometime between 2033-2066. Importantly, even though the strength of the signal will depend on the interior properties of the pulsar, the expected dates of signal arrival are completely model independent, depending only on the locations of the source and the relevant pulsar.

    Comments:
    5 pages, 1 figure, 2 tables
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); Nuclear Theory (nucl-th)
    arXiv:
    1909.04476 [pdf]
    PLB(2020)·3 citations
  6. 07

    [Submitted on 10 Sept 2019] (cross-list from hep-ph)

    The Shear Viscosity to Entropy Density Ratio of Hagedorn States

    Jan Rais🇩🇪 · Kai Gallmeister🇩🇪 · Carsten Greiner🇩🇪

    The fireball concept of Rolf Hagedorn, developed in the 1960's, is an alternative description of hadronic matter. Using a recently derived mass spectrum, we use the transport model GiBUU to calculate the shear viscosity of a gas of such Hagedorn states, applying the Green-Kubo method to Monte-Carlo calculations. Since the entropy density is rising ad infinitum near , this leads to a very low shear viscosity to entropy density ratio near . Further, by comparing our results with analytic expressions, we find a nice extrapolation behavior, indicating that a gas of Hagedorn states comes close or even below the boundary from AdS-CFT.

    Comments:
    7 pages, 8 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1909.04522 [pdf]
    PRD(2020)·17 citations
  7. 08

    [Submitted on 10 Sept 2019] (cross-list from hep-ph)

    Universality driven analytic structure of the QCD crossover: radius of convergence in the baryon chemical potential

    Swagato Mukherjee🇺🇸 · Vladimir Skokov🇺🇸

    Recent lattice QCD calculations strongly indicate that the chiral crossover of QCD at zero baryon chemical potential \mu_B is a remnant of the second-order chiral phase transition. Universal properties of this second-order phase transition can be mapped to QCD temperature T and \mu_B using non-universal parameters determined by lattice QCD recently. Motivated by these results, first, we discuss the analytic structure of the partition function in the QCD crossover regime - the so-called Yang-Lee edge singularity - solely based on universal properties. Next, utilizing the lattice QCD results for non-universal parameters we map this singularity to the real T and complex \mu_B plane, leading to the determination of the radius of convergence is in \mu_B in the QCD crossover regime. These universality- and QCD-based results provide tight constraints on the range of validity of the lattice QCD calculations at \mu_B. Implication of this result on the location of the conjectured QCD critical point is discussed.

    Comments:
    5 pages, 3 figures; published version
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1909.04639 [pdf]
    PRD(2021)·55 citations

Affiliations

first authorsco-authorsvia INSPIRE