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Nuclear Theory·nucl-th

Tuesday·October 10, 2023

11 papers—5 primary·6 cross-listed

All11Primary5Cross-lists6
  1. 06

    Impact of global monopole on heavy mesons in hot-dense medium

    M. Abu-Shady🇪🇬 · Faizuddin Ahmed🇮🇳

    This research study is primarily focus on investigating how the topological effects influence the eigenvalue solutions in the presence of a hot-dense medium. To accomplish this, we employ the non-relativistic Schrödinger wave equation, taking into consideration both the quantum flux field and an interaction potential. Through this approach, we determine the energy eigenvalues and their corresponding wave functions using the Nikiforov-Uvarov method. Our findings indicate that when we consider both the topological effects and the magnetic flux, , there is a noticeable reduction in the binding energy within the hot-dense medium. Additionally, we analyze the role of the baryonic potential in shaping the binding energy within the plane. Interestingly, it is evident that the influence of the baryonic potential becomes more pronounced as its values decrease

    ↳ hep-thnucl-thquant-phInt.J.Mod.Phys.A(2024)·2 citations
  2. 07

    Candidate toroidal electric dipole mode in the spherical nucleus Ni

    P. von Neumann-Cosel (1) · V.O. Nesterenko (2,3) · I. Brandherm (1) · P.I. Vishnevskiy (2,4) · P.-G. Reinhard (5) · J. Kvasil (6) · H. Matsubara (7,8) · A. Repko (9) · A. Richter (1) · M. Scheck (10,11) · A. Tamii (7) ((1) Institut für Kernphysik, Technische Universität Darmstadt, Darmstadt, Germany, (2) Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Russia, (3) State University "Dubna", Dubna, Moscow region, Russia, (4) Institute of Nuclear Physics Almaty, Almaty Region, Kazakhstan, (5) Institut für Theoretische Physik II, Universität Erlangen, Erlangen, Germany, (6) Institute of Particle and Nuclear Physics, Charles University, Praha, Czech Republic, (7) Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka, Japan, (8) Faculty of Radiological Technology, Fujita Health University, Aichi, Japan, (9) Institute of Physics, Slovak Academy of Sciences, Bratislava, Slovakia, (10) School of Computing, Engineering, and Physical Sciences, University of the West of Scotland, Paisley, United Kingdom, (11) Scottish Universities Physics Alliance, United Kingdom)

    Dipole toroidal modes appear in many fields of physics. In nuclei, such a mode was predicted more than 50 years ago, but clear experimental evidence was lacking so far. Using a combination of high-resolution inelastic scattering experiments with photons, electrons and protons, we identify for the first time candidates for toroidal dipole excitations in the nucleus Ni and demonstrate that transverse electron scattering form factors represent a relevant experimental observable to prove their nature.

    ↳ nucl-exnucl-thPRL(2024)·18 citations
  3. 08

    On the Microscopic Level Density Models for Nuclei Near Z=28 Shell Closure

    Surayya H.E (1) · Jesmi Sunny (1) · M.M Musthafa (1) · C.V Midhun (1) · S.V Suryanarayana (2) · Jyoti Pandey (3) · A Pal (2) · P.C Rout (2) · S Santra (2) · Antony Joseph (1) · S. Ganesan (4). (Department of Physics, University of Calicut, Kerala, India (1), Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India (2), Inter University Accelerator Centre, New Delhi, Delhi 110067, India (3) and Formarly Raja Ramanna Fellow, Bhabha Atomic Research Centre, Mumbai 400085, India (4))

    A comprehensive test of level density models for explaining the decay of excited compound nuclei, 54 Mn, 56 Fe, 58 Co, 60 Ni, 61 Ni and 63 Cu, in the energy range of 28 - 36 MeV has been performed. The compound nuclei of interest in the desired ranges are populated using 6 Li based transfer reactions. The proton decay spectrum for each excitation energy bins has been measured. The measured proton spectrum has been reproduced using statistical model calculations with different level density models. A variance minimised approach has been employed for analysing the prediction capability of different level density models. This approach has been converged to Gogny Hartree-Fock-Bogoliubov(HFB) microscopic level density model and which is attributed as the most accurate model for the desired nuclei.

    ↳ nucl-exnucl-thPRC(2025)·0 citations
  4. 09

    Normal mode analysis within a mutilated relaxation time approximation

    Jin Hu🇨🇳

    In this paper, we present a detailed analysis of normal modes based on the Boltzmann equation within the mutilated relaxation time approximation (RTA). Using this linearized effective kinetic description, our analysis encompasses a complete order calculation in wavenumber k, extending the conventional hydrodynamic mode analysis to intermediate and short-wavelength regions. Furthermore, our linear mode analysis can provide a natural classification of kinetic modes into collective modes and non-collective single-particle excitations. In the case of an energy-independent relaxation time, the behavior of hydrodynamic onset transitions is recovered (Romatschke in Eur Phys J C 76:352, 2016). However, for the case with an energy-dependent relaxation time, the distinct classification becomes less clear, as the location of hydrodynamic modes is not well separated from non-hydrodynamic modes.

    ↳ hep-phnucl-thEPJC(2025)·4 citations
  5. 10

    A new approach to the 3-momentum regularization of the in-medium one and two fermion line integrals with applications to cross sections in the Nambu--Jona-Lasinio model

    Renan Câmara Pereira🇵🇹 · João Moreira🇵🇹 · Pedro Costa🇵🇹 · Constança Providência🇵🇹

    We propose the 3-momentum sphere intersection regularization applied to the one and two fermion line integrals at finite temperature and chemical potential. The quark-antiquark polarization function in this new regularization approach is equivalent to the usual 3-momentum regularization, when the absolute value of the external 3-momentum of the polarization is zero. Additionally, it respects the particle-antiparticle symmetry of meson states in the NambuJona-Lasinio (NJL) model for all values of temperature and chemical potential. Without this symmetry, in-medium cross sections calculated in the 3-momentum regularized NJL model are not consistent. In order to demonstrate the difference between the usual 3-momentum regularization with the one proposed in this work, we study the quark-quark and quark-antiquark cross sections in both regularization schemes. To this end we use the standard NJL model, with four and six quark interactions. We observe major quantitative and qualitative differences when comparing quark-quark cross sections in both schemes. The quark-antiquark cross sections, on the other hand, are very similar in both regularizations, owning to the equivalence between the regularizations when the absolute value of the external 3-momentum is zero.

    ↳ hep-phnucl-thPRC(2024)·1 citation
  6. 11

    Collective modes of a massive fermion in a magnetized medium with finite anomalous magnetic moment

    Nilanjan Chaudhuri🇮🇳 · Snigdha Ghosh🇮🇳 · Pradip Roy🇮🇳 · Sourav Sarkar🇮🇳

    We calculate, in a systematic way, the general structure of the self-energy of light massive fermions and the effective propagator in a thermomagnetic medium with the inclusion of anomalous magnetic moment (AMM) of the fermion in the weak field approximation. It is found that the self-energy of a massive fermion in this case consists of five non-trivial structure factors in contrast to the massless case where the self-energy contains only four. We employ the real time formalism (RTF) of thermal field theory within the ambit of hard thermal loop (HTL) approximation in the evaluation of the structure factors. The collective modes are obtained from the poles of the effective propagator of the fermion. The investigation of the dispersion relations for non-degenerate ground state shows that the effect of the magnetic field is more for up quark than the down quark because of the larger charge of the former. The important observation is that in the first excited state the degeneracy, which exists for non-zero magnetic field is lifted due to the inclusion of the AMM. It is also observed that the first excited state becomes less dispersive compared to the case when AMM is not considered, whereas the second excited state becomes more dispersive when both the magnetic field and the AMM are non-zero in comparison to the case with vanishing AMM. These effects are observed in both particle and hole-like excitations. Qualitatively similar behaviour is also seen in the case of down quarks.

    ↳ hep-phnucl-thPRD(2023)·9 citations

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