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Nuclear Theory·nucl-th

Monday·September 7, 2020

7 papers—4 primary·3 cross-listed

All7Primary4Cross-lists3
  1. 01

    [Submitted on 4 Sept 2020]

    Effects of ground-state correlations on magnetic dipole excitations in Ca

    Mitsuru Tohyama

    The effects of ground-state correlations on the magnetic dipole excitations in Ca are studied using an extended random phase approximation (ERPA) derived from the time-dependent density-matrix theory. Comparison is made with other extended RPA approaches, the renormalized RPA, the self-consistent RPA and the extended second RPA which also include the effects of ground-state correlations. It is pointed out that direct excitations from two particle - two hole space which are properly treated in ERPA cause strong magnetic dipole transitions in Ca.

    Comments:
    5 pages, 4 figures. arXiv admin note: text overlap with arXiv:1712.02006
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2009.02014 [pdf]
    1 citation
  2. 02

    [Submitted on 4 Sept 2020]

    Electron-capture decay in isotopic transfermium chains from self-consistent calculations

    Pedro Sarriguren

    Weak decays in heavy nuclei with charge numbers Z=101-109 are studied within a microscopic formalism based on deformed self-consistent Skyrme Hartree-Fock mean-field calculations with pairing correlations. The half-lives of beta+ decay and electron capture are compared with alpha-decay half-lives obtained from phenomenological formulas. Transfermium isotopes of Md, No, Lr, Rf, Db, Sg, Bh, Hs, and Mt that can be produced in the frontier of cold and hot fusion-evaporation channels are considered. Several isotopes are identified whose beta+/EC- and alpha-decay half-lives are comparable. The competition between these decay modes opens the possibility of new pathways towards the islands of stability.

    Comments:
    14 pages, 10 figures, accepted for publication in Journal of Physics G
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2009.02103 [pdf]
    J.Phys.G(2020)·9 citations
  3. 03

    [Submitted on 4 Sept 2020]

    Bose-Einstein Condensation of Quantum Hard-Spheres as a Deposition Phase Transition and New Relations Between Bosonic and Fermionic Pressures

    Kyrill A. Bugaev · Oleksii I. Ivanytskyi · Boris E. Grinyuk · Ivan P. Yakimenko

    We investigate the phase transition of Bose-Einstein particles with the hard-core repulsion in the grand canonical ensemble within the Van der Waals approximation. It is shown that the pressure of non-relativistic Bose-Einstein particles is mathematically equivalent to the pressure of simplified version of the statistical multifragmentation model of nuclei with the vanishing surface tension coefficient and the Fisher exponent , which for such parameters has the 1-st order phase transition. The found similarity of these equations of state allows us to show that within the present approach the high density phase of Bose-Einstein particles is a classical macro-cluster with vanishing entropy at any temperature which, similarly to the classical hard spheres, is a kind of solid state. To show this we establish new relations which allow us to identically represent the pressure of Fermi-Dirac particles in terms of pressures of Bose-Einstein particles of two sorts.

    Comments:
    8 pages
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2009.02178 [pdf]
    Ukr.J.Phys.(2020)·1 citation
  4. 04

    [Submitted on 4 Sept 2020]

    Initial State Summary of Hard Probes 2020

    Bjoern Schenke🇺🇸

    The description of the initial state of heavy ion collisions, which covers the description of the incoming nuclei, the initial hard and soft interactions, the resulting spatial geometry of the produced matter, as well as the dynamic approach to a medium well described by hydrodynamics, has important consequences for the study of hard and electromagnetic probes. I will review new developments presented at Hard Probes 2020 that have an impact on these aspects of our understanding of the initial state of heavy ion and smaller system collisions.

    Comments:
    8 pages, 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions (Hard Probes 2020)
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2009.02278 [pdf]
    0 citations
  5. 05

    [Submitted on 4 Sept 2020] (cross-list from hep-ph)

    Deciphering the charged heavy quarkoniumlike states in chiral effective field theory

    Bo Wang🇨🇳 · Lu Meng🇨🇳 · Shi-Lin Zhu🇨🇳

    We generalize the framework of chiral effective field theory to study the interactions of the isovector and systems up to the next-to-leading order, in which the long-, mid-, and short-range force contributions as well as the - wave mixing are incorporated. Based on the Lippmann-Schwinger equation, we fit the invariant mass distributions of the elastic channels measured by the BESIII and Belle Collaborations. Our results indicate that the four charged charmoniumlike and bottomoniumlike states , and , can be well identified as the and molecular resonances. The bound state explanations are vetoed in our framework. Our study favors the and states are the twin partners under the heavy quark symmetry.

    Comments:
    6 pages, 3 figures and 1 table
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2009.01980 [pdf]
    PRD(2020)·30 citations
  6. 06

    [Submitted on 4 Sept 2020] (cross-list from hep-ph)

    Progress on 3+1D Glasma simulations

    Andreas Ipp🇦🇹 · David I. Müller🇦🇹

    We review our progress on 3+1D Glasma simulations to describe the earliest stages of heavy-ion collisions. In our simulations we include nuclei with finite longitudinal extent and describe the collision process as well as the evolution of the strongly interacting gluonic fields in the laboratory frame in 3+1 dimensions using the colored particle-in-cell method. This allows us to compute the 3+1 dimensional Glasma energy-momentum tensor, whose rapidity dependence can be compared to experimental pion multiplicity data from RHIC. An improved scheme cures the numerical Cherenkov instability and paves the way for simulations at higher energies used at LHC.

    Comments:
    9 pages, 5 figures, invited contribution to EPJA topical issue "Theory of Hot Matter and Relativistic Heavy-Ion Collisions (THOR)"
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2009.02044 [pdf]
    EPJA(2020)·22 citations
  7. 07

    [Submitted on 4 Sept 2020] (cross-list from hep-ph)

    Jet suppression from small to large radius

    Daniel Pablos🇳🇴

    The angular dependence of jet suppression encodes key information about the process of energy and momentum hydrodynamization, and for this reason can be used to greatly improve our understanding of fundamental aspects of the jet/QGP interaction. In this work we study jet suppression from small to very large radius, for low and very high energy jets at the LHC and RHIC. We use the hybrid strong/weak coupling model for jet quenching that combines perturbative shower evolution with an effective strongly coupled description of the energy and momentum transfer from the jet into the QGP. Because of energy-momentum conservation, the wake created by the jet enhances or depletes the yield of particles generated at the freeze-out hypersurface depending on their orientation with respect to the direction of the jet. We find that jet suppression is remarkably independent of the anti- radius R, specially at LHC, first slightly increasing by opening R, then at larger values of R slowly decreasing. This nearly independence of jet suppression with R arises from two competing effects, namely the larger energy loss of the energetic jet components, which tends to increase suppression, against the partial recovery of the lost energy due to medium response, which reduces suppression. We find that the boosted medium from the recoiling jet depletes the amount of QGP in the direction opposite to it in the transverse plane, inducing energy loss due to an over-subtraction effect. We show that this unique signature of the hydrodynamization of part of the jet energy can be scrutinized by selecting samples of dijet configurations with different relative rapidities between the leading and the subleading jet.

    Comments:
    4 pages, 2 figures, 10th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2009.02202 [pdf]
    PoS(2021)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE