PaperPanorama

Nuclear Theory·nucl-th

Monday·December 25, 2023

10 papers4 primary·6 cross-listed

  1. 01

    Pairing effects on pure rotational energy of nuclei

    K. Abe · H. Nakada

    By applying the angular-momentum projection (AMP) to the self-consistent axial mean-field solutions with the semi-realistic effective Hamiltonian M3Y-P6, the pairing effects on the pure rotational energy of nuclei, \textit{i.e.}, the rotational energy at a fixed intrinsic state, have been investigated. While it was shown at the Hartree-Fock (HF) level that the individual terms of the Hamiltonian contribute to the rotational energy with ratios insensitive to nuclides except for light or weakly-deformed nuclei, the pair correlations significantly change the contributions, even for the well-deformed heavy nuclei. The contribution of the interaction to the rotational energy is found to correlate well with the degree of proximity between nucleons, which is measured via the expectation value that two nucleons exist at the same position. While the nucleons slightly spread as the angular momentum increases at the HF level, accounting for the positive (negative) contribution of the attractive (repulsive) components of the interaction, the pair correlations reduce or invert the effect.

    nucl-thJ.Phys.G(2024)·1 citation
  2. 02

    Systematic study of the rotational bands in the mass region

    Anshul Dadwal · Xiao-Tao He

    For the first time, we conducted a comprehensive analysis of the rotational bands in the \( A\sim250 \) mass region. Utilizing a variety of rotational energy models and formulas, we have extracted free parameters for 36 rotational bands within this mass region, encompassing neutron numbers from N = 148 to 152. A significant enhancement has been made to the vibrational distortion model, leading to an exceptional match with the experimental data on dynamic moment of inertia across most of the rotational bands studied. Through the application of this revised model, we have categorized the dynamic moment of inertia into three distinct groups. The implications of the modified vibrational distortion term and how it evolves with changes in rotational frequency is also investigated. Our systematic investigation brings to light the peculiar behavior of Pu isotopes, especially in ground state bands of \( ^{242,244}\text{Pu}\), within this mass region. We provide a thorough discussion on various aspects such as the role of shape-fluctuation energy, the softness parameter, band-head and average moment of inertia, the prominence of the anti-pairing effect, and the transition from pairing to anti-pairing effects in Pu isotopes. Moreover, these findings are compared with other isotones, offering a comprehensive understanding of their unique characteristics.

    nucl-th0 citations
  3. 03

    Entanglement in few-nucleon scattering events

    Tanja Kirchner · Wael Elkamhawy · Hans-Werner Hammer

    We investigate the spin entanglement in few-nucleon scattering processes involving nucleons and deuterons. For this purpose, we consider the entanglement power introduced by Beane et al. We analyze different entanglement entropies as a basis to define the entanglement power of the strong interaction and calculate the corresponding entanglement powers for proton-neutron, neutron-deuteron, proton-deuteron, and deuteron-deuteron scattering. For the latter two processes, we also take into account the modification from the Coulomb interaction. In contrast to proton-neutron scattering, no universal low-energy features are evident in the spin entanglement in neutron-deuteron, proton-deuteron, and deuteron-deuteron scattering.

    nucl-thquant-phFew Body Syst.(2024)·26 citations
  4. 04

    Can we observe effects of early nonequilibrium dynamics using collective flow

    Piotr Bozek

    The rapid expansion of the fireball created in a heavy-ion collision causes strong departures from local equilibrium. Such effects are especially important in the very early phase of the collision, bringing a substantial pressure asymmetry. We investigate effects of this early stage pressure asymmetry in a kinetic model without boost-invariance. In the kinetic evolution the pressure asymmetry results from the competition of the longitudinal expansion and the kinetic relaxation. Unlike the transverse flow, the directed flow is found to be very sensitive to the equilibration rate and the pressure anisotropy.

    nucl-thEPJ Web Conf.(2024)·0 citations
  5. 05

    iDMEu: An initiative for Dark Matter in Europe and beyond

    Marco Cirelli🇫🇷 · Caterina Doglioni🇬🇧 · Federica Petricca🇩🇪

    We introduce the initiative for Dark Matter in Europe and beyond (iDMEu), a collective effort by a group of particle and astroparticle physicists to set up an online resource meta-repository, a common discussion platform and a series of meetings on everything concerning Dark Matter. This document serves as a status report as well as a citable item concerning iDMEu.

    hep-phastro-ph.COastro-ph.GAhep-ex+1PoS(2024)·1 citation
  6. 06

    Numerical evidence for fractional topological objects in SU(3) gauge theory

    Jackson A. Mickley🇦🇺 · Waseem Kamleh🇦🇺 · Derek B. Leinweber🇦🇺

    The continued development of models that propose the existence of fractional topological objects in the Yang-Mills vacuum has called for a quantitative method to study the topological structure of gauge theory. We present an original numerical algorithm that can identify distinct topological objects in the nontrivial ground-state fields and approximate the net charge contained within them. This analysis is performed for colour at a range of temperatures crossing the deconfinement phase transition, allowing for an assessment of how the topological structure evolves with temperature. We find a promising consistency with the instanton-dyon model for the structure of the QCD vacuum at finite temperature. Several other quantities, such as object density and radial size, are also analysed to elicit a further understanding of the fundamental structure of ground-state gluon fields.

    hep-lathep-phnucl-thPRD(2024)·8 citations
  7. 07

    Heavy flavor transport and observables in heavy-ion collisions within the MARTINI+MUSIC framework

    Manu Kurian🇨🇦 · Mayank Singh🇺🇸 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

    We study the transport dynamics of charm quarks within an expanding quark-gluon plasma for Pb+Pb collisions at 2.76 TeV. The analysis incorporates the hydrodynamical approach-MUSIC with fluctuating IP-Glasma initial state and Bayesian-quantified viscous coefficients. We study the interaction strength of charm quarks in the medium, including elastic collisional processes with medium constituents, gluon emission processes, and the impact of non-perturbative interactions on heavy quark transport. Further, we analyze the dynamics of heavy flavors using a hybrid framework that incorporates the MARTINI event generator, with PYTHIA8.1 for the initial production of heavy quarks, and Langevin dynamics to describe the evolution of heavy quarks.

    hep-phnucl-th0 citations
  8. 08

    Dynamically generated axial-vector meson resonance in the chiral symmetry restored vacuum

    Jisu Kim🇰🇷 · Su Houng Lee🇰🇷

    We study the modification of the properties of the axial-vector meson, dynamically generated through the unitarization procedure, in the vacuum where the chiral symmetry is restored. This is accomplished by scaling the pion decay constant as the chiral order parameter while keeping the other input parameters fixed. We find that the mass and width of the axial-vector meson reduce to those of the vector meson, as anticipated by the Weinberg sum rules. The findings are consistent with the results of a recent QCD sum rule calculation, wherein the chiral order parameter is expressed through chiral symmetry-breaking four-quark operators, leading to the mass-squared difference scaling in proportion to variations in the chiral order parameter. We calculate the scaling behavior for the mass differences obtained from the unitarization method using both the physical and massless pion masses.

    hep-phnucl-th0 citations
  9. 09

    Hot spots in a proton

    S. Demirci🇫🇮 · T. Lappi🇫🇮 · S. Schlichting🇩🇪

    We explore the consequences of gluonic hot spots inside the proton for the initial eccentricities in a proton-nucleus collision, and the constraints on the parameters describing these hot spots from coherent and incoherent exclusive vector meson production cross sections in deep inelastic scattering. We show that geometric fluctuations of hot spots inside the proton are the dominant source of eccentricity whereas color charge fluctuations only give a negligible correction. We find that the coherent cross section is sensitive to both the size of the target and the structure of the probe. The incoherent cross section is dominated by color fluctuations at small transverse momentum transfer (t), by proton and hot spot sizes as well as the structure of the probe at medium -t and again by color fluctuations at large -t.

    hep-phnucl-thEPJ Web Conf.(2024)·1 citation
  10. 10

    Thermalization and quark production in spatially homogeneous systems of gluons

    Sergio Barrera Cabodevila🇪🇸 · Carlos A. Salgado🇪🇸 · Bin Wu🇪🇸

    We first assemble a full set of the Boltzmann Equation in Diffusion Approximation (BEDA) for studying thermalization/hydrodynamization and quark production in out of equilibrium systems. We then discuss thermalization and the production of three flavors of massless quarks in spatially homogeneous systems initially filled only with gluons. A complete parametric understanding for thermalization and quark production is obtained for both initially very dense or dilute systems, which are complemented by detailed numerical simulations. For initial distributions more relevant for heavy-ion collisions, the complete thermal equilibration is found to be significantly delayed by considering quark production.

    hep-phnucl-thEPJ Web Conf.(2024)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE