PaperPanorama
FAQ

Nuclear Theory·nucl-th

Tuesday·May 17, 2022

8 papers—6 primary·2 cross-listed

All8Primary6Cross-lists2
  1. 01

    [Submitted on 14 May 2022]

    New Insights into Backbending in the Symmetry-adapted Framework

    Nicholas D. Heller · Grigor H. Sargsyan · Kristina D. Launey · Calvin W. Johnson · Tomáš Dytrych · Jerry P. Draayer

    We provide new insights into backbending phenomenon within the symmetry-adapted framework which naturally describes the intrinsic deformation of atomic nuclei. For , the canonical example of backbending in light nuclei, the ab initio symmetry-adapted no-core shell model shows that while the energy spectrum replicates the backbending from experimental energies under the rigid rotor assumption, there is no change in the intrinsic deformation or intrinsic spin of the yrast band around the backbend. For the traditional example of , computed in the valence shell with empirical interactions, we confirm a high-spin nucleus that is effectively spherical, in agreement with previous models. However, we find that this spherical distribution results, on average, from an almost equal mixing of deformed prolate shapes with deformed oblate and triaxial shapes. Microscopic calculations confirm the importance of spin alignment and configuration mixing, but surprisingly unveil no anomalous increase in moment of inertia. This finding opens the path toward further understanding the rotational behavior and moment of inertia of medium-mass nuclei.

    Comments:
    11 pages, 7 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2205.06943 [pdf]
    PRC(2023)·10 citations
  2. 02

    [Submitted on 14 May 2022]

    Modeling survival probabilities of superheavy nuclei at high excitations

    C.Y. Qiao · J.C. Pei

    This work investigated the first-chance survival probabilities of highly excited compound superheavy nuclei in the prospect of synthesizing new superheavy elements. The main feature of our modelings is the adoption of microscopic temperature dependent fission barriers in calculations of fission rates. A simple derivation is demonstrated to elucidate the connection between Bohr-Wheeler statistical model and imaginary free energy method, obtaining a new formula for fission rates. The best modeling is chosen with respect to reproducing the experimental fission probability of Po. Systematic studies of fission and survival probabilities of No, Fl, Og, and =120 compound nuclei are performed. Results show large discrepancies by different models for survival probabilities of superheavy nuclei although they are close for Po. We see that the first-chance survival probabilities of =120 are comparable to that of Fl and Og.

    Comments:
    8 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2205.07080 [pdf]
    PRC(2022)·7 citations
  3. 03

    [Submitted on 14 May 2022]

    Uncertainty Quantification in Breakup Reactions

    Özge Sürer · Filomena M. Nunes · Matthew Plumlee · Stefan M. Wild

    Breakup reactions are one of the favored probes to study loosely bound nuclei, particularly those in the limit of stability forming a halo. In order to interpret such breakup experiments, the continuum discretized coupled channel method is typically used. In this study, the first Bayesian analysis of a breakup reaction model is performed. We use a combination of statistical methods together with a three-body reaction model (the continuum discretized coupled channel method) to quantify the uncertainties on the breakup observables due to the parameters in the effective potential describing the loosely bound projectile of interest. The combination of tools we develop opens the path for a Bayesian analysis of not only breakup processes, but also a wide array of complex processes that require computationally intensive reaction models.

    Subjects:
    Nuclear Theory (nucl-th); Data Analysis, Statistics and Probability (physics.data-an)
    arXiv:
    2205.07119 [pdf]
    PRC(2022)·22 citations
  4. 04

    [Submitted on 15 May 2022]

    Fluctuations in the canonical ensemble of an Abelian charge

    Bengt Friman (Darmstadt, GSI)🇩🇪 · Krzysztof Redlich (Wroclaw U.)🇵🇱

    We study fluctuations in the canonical ensemble, where the net baryon number is exactly conserved. The focus is on cumulants and factorial cumulants linked to the baryon and antibaryon multiplicities and their sum or difference in full phase-space as well as in subsystems. In particular, we connect the fluctuations of the net baryon number in a subsystem, relevant for fluctuation studies in nucleus-nucleus collisions, with fluctuations of the baryon and antibaryon numbers of the total system. We derive analytic expressions for factorial cumulants of arbitrary order. Compact results are obtained in terms of cumulants of the baryon number of the total system. Moreover, we derive the asymptotic forms of the factorial cumulants of baryon and antibaryon multiplicities in the high- and low-temperature limits and discuss the results in the context of heavy-ion collision experiments.

    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2205.07332 [pdf]
    7 citations
  5. 05

    [Submitted on 16 May 2022]

    Probe the color screening in proton-nucleus collisions with complex potentials

    Liuyuan Wen🇨🇳 · Xiaojian Du🇨🇳 · Shuzhe Shi🇨🇳 · Baoyi Chen🇨🇳

    Color screening and parton inelastic scattering modify the heavy-quark antiquark potential in the medium that consists of particles from quantum chromodynamics (QCD), leading to suppression of quarkonium production in relativistic heavy-ion collisions. Due to small charm/anti-charm () pair production number in proton-nucleus (pA) collisions, the correlation between different pairs is negligible, which makes the Schrödinger equation viable for tracking the evolution of only one pair. We employ the time-dependent Schrödinger equation with in-medium potential to study the evolution of charmonium wave functions in the hydrodynamic like QCD medium produced in pA collisions. We explore different parametrizations of real and imaginary parts of potential and calculate the nuclear modification factors () of and in TeV energy p-Pb collisions at Large Hadron Collider (LHC). Comparing a strong and a weak screening scenario with experimental data in this approach, we arrive at the conclusion that the color screening is weak at temperature close to deconfined phase transition. Moreover, the imaginary part of the potential is crucial to describe the experimental data which is consistent with widely studied semi-classical approaches where the dissociation rates are essential.

    Comments:
    9 pages, 8 figures, accepted by Chinese Physics C
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2205.07520 [pdf]
    CPC(2022)·17 citations
  6. 06

    [Submitted on 16 May 2022]

    A fluid-dynamic approach to heavy-quark diffusion in the quark-gluon plasma

    F. Capellino🇩🇪 · A. Beraudo🇮🇹 · A. Dubla🇩🇪 · S. Floerchinger🇺🇸 · S. Masciocchi🇩🇪 · J. Pawlowski🇩🇪 · I. Selyuzhenkov🇩🇪

    A fluid-dynamic approach to the diffusion of heavy quarks in the quark--gluon plasma (QGP) is presented. Specifically, we analyze the Fokker-Planck equation for the momentum transport of heavy quarks from a fluid perspective and use a mapping to second-order fluid-dynamics to determine conductivities and relaxation times governing their spatial diffusion. By investigating the relation between the two approaches, we provide new insights concerning the level of local thermalization of charm and bottom quarks inside the expanding QGP. Our results indicate that a fluid-dynamic description of diffusion is feasible for charm quarks at least for the latest stages of the fireball evolution.

    Comments:
    8 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2205.07692 [pdf]
    PRD(2022)·26 citations

Affiliations

first authorsco-authorsvia INSPIRE