PaperPanorama

Nuclear Theory·nucl-th

Monday·January 14, 2019

6 papers4 primary·2 cross-listed

  1. 01

    Exploring the accurate nuclear potential

    D. K. Swami · Yash Kumar · T. Nandi

    We have constructed empirical formulae for fusion and interaction barrier heights using experimental values available in the literature. Fusion excitation function measurements are used for the former and back angle quasi-elastic excitation function for the latter case. The fusion barriers so obtained have been compared with various model predictions such as Bass potential, Christenson and Winther, Broglia and Winther, Aage Winther, Siwek-Wilczynska and J.Wilczynski, Skyrme energy density function model, and the Sao Paulo optical potential along with experimental results. The comparison allows us to find the best model, which is found to be the Broglia and Winther model. Further, to examine its predictability, the Broglia and Winther model parameters are used to obtain total fusion cross sections showing good agreement with the experimental values for beam energies above the fusion barriers. Thus, this model can be useful for planning any experiments, especially ones aiming for super heavy elements. Similarly, current interaction barrier heights have also been compared with the Bass potential model predictions. It shows that the present model calculations are much lower than the Bass potential model predictions. We believe the current interaction barrier model prediction will be a good starting point for future quasi-elastic scattering experiments. Whereas both the Broglia and Winther model and our interaction barrier model will have practical implications in carrying out physics research near the Coulomb barrier energies.

    nucl-th0 citations
  2. 02

    An extended Agassi model: algebraic structure, phase diagram, and large size limit

    J.E. García-Ramos🇪🇸 · J Dukelsky🇪🇸 · P Pérez-Fernández🇪🇸 · J.M. Arias🇪🇸

    The Agassi model is a schematic two-level model that involves pairing and monopole-monopole interactions. It is, therefore, an extension of the well known Lipkin-Meshkov-Glick (LMG) model. In this paper we review the algebraic formulation of an extension of the Agassi model as well as its bosonic realization through the Schwinger representation. Moreover, a mean-field approximation for the model is presented and its phase diagram discussed. Finally, a analysis, with proportional to the degeneracy of each level, is worked out to obtain the thermodynamic limit of the ground state energy and some order parameters from the exact Hamiltonian diagonalization for finite.

    nucl-thPhys.Scripta(2019)·3 citations
  3. 03

    Medium modified leading hadrons, jets and sub-jets in a single formalism

    Chathuranga Sirimanna🇺🇸 · Shanshan Cao🇺🇸 · Abhijit Majumder🇺🇸

    Vacuum and medium modified fragmentation functions are used to study the properties of hadrons produced in hard interactions, in - and - collisions, respectively. We study the modification of reconstructed jets and high transverse momentum (high-) hadrons as they propagate through a dense medium. Jets and jet modification are studied within the framework of a factorized jet function. The vacuum jet function is found consistent with PYTHIA simulations. Both the modification of the fragmentation function and the jet function are carried out within the identical higher-twist energy loss formalism. This approach is then extended to di-hadron production within a jet. Its further extension to a "di-prong" function and its application to the soft-drop measurements are discussed. The methodology of extending these semi-analytical calculations to full Monte-Carlo simulations is outlined. All calculations are carried out within a (2+1)-D viscous hydrodynamic simulation and compared to experimental data from a variety of collision energies.

    nucl-thPoS(2019)·4 citations
  4. 04

    Efimov universality with Coulomb interaction

    C.H. Schmickler · H.-W. Hammer · E. Hiyama

    The universal properties of charged particles are modified by the presence of a long-range Coulomb interaction. We investigate the modification of Efimov universality as a function of the Coulomb strength using the Gaussian expansion method. The resonant short-range interaction is described by Gaussian potentials to which a Coulomb potential is added. We calculate binding energies and root mean square radii for the three- and four-body systems of charged particles and present our results in a generalised Efimov plot. We find that universal features can still be discerned for weak Coulomb interaction, but break down for strong Coulomb interaction. The root-mean-square radius plateaus at increasingly smaller values for strong Coulomb interaction and the probablity distributions of the states become more concentrated inside the Coulomb barrier. As an example, we apply our universal model to nuclei with an alpha-cluster substructure. Our results point to strong non-universal contributions in that sector.

    nucl-thcond-mat.quant-gasphysics.atm-clusEPJA(2019)·4 citations
  5. 05

    Bose polaron in spherically symmetric trap potentials: Ground states with zero and lower angular momenta

    Kano Watanabe · Eiji Nakano · Hiroyuki Yabu

    Single-atomic impurities immersed in a dilute Bose gas in the spherically symmetric harmonic trap potentials are studied at zero temperature. In order to find the ground state of the polarons, we present a conditional variational method with fixed expectation values of the total angular momentum operators, and , of the system, using a cranking gauge-transformation for bosons to move them in the frame co-rotating with the impurity. In the formulation, the expectation value is shown to be shared in impurity and bosons, but the value is carried by the impurity due to the rotational symmetry. We also analyze the ground-state properties numerically obtained in this variational method for the system of the attractive impurity-boson interaction, and find that excited boson distributions around the impurity overlap largely with impurity's wave function in their quantum-number spaces and also in the real space because of the attractive interaction employed.

    cond-mat.quant-gasnucl-thPRA(2019)·3 citations
  6. 06

    Effect of Scalar Boson on Fermionic Dark Star

    A. B. Wahidin🇮🇩 · A. Rahmansyah🇮🇩 · A. Sulaksono🇮🇩

    The role of scalar boson exchange as a mediator of the fermionic dark particle interaction and the mass of dark particle on the bulk properties of fermionic dark stars including their moment of inertia and tidal deformability are studied. We have found that the role of the attractive nature of the scalar boson exchange and the fermionic dark particle mass can control the stiffness of the fermionic dark star equation of state. By increasing the strength of scalar boson coupling, the fermionic dark star becomes more compact. As a consequence, if scalar boson exchange contribution is included the compactness of a dark star can exceed =0.22. We also compare the fermionic dark stars moment of inertia and tidal deformability to those of neutron stars (with and without hyperons in neutron star core) predicted by relativistic mean field model. It is evidence that the properties of both types of stars are quite different. We also have found that the universal I-Love relation in fermionic dark stars is not affected by scalar boson exchange contribution and the fermionic dark particle mass. Possible observations of fermionic dark stars are also discussed.

    gr-qcastro-ph.SRhep-phnucl-thInt.J.Mod.Phys.D(2019)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE