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Nuclear Theory·nucl-th

Wednesday·April 4, 2018

3 papers—2 primary·1 cross-listed

All3Primary2Cross-lists1
  1. 01

    Magnetic rotations in 198Pb and 199Pb within covariant density functional theory with pairing correlations

    Yakun Wang

    The observed shears bands in 198Pb and 199Pb are investigated within the framework of tilted axis cranking covariant density functional theory, and the separable pairing force is adopted to consider the pairing correlations. The energy spectra, total angular momenta, and transition probabilities agree well with the experimental data. The bandhead energy differences are reproduced satisfactorily without any ad hoc renormalizations when the pairing correlations are taken into account. The angular momentum vectors are discussed in detail to analyze the pairing effects on magnetic rotations.

    nucl-thPRC(2018)·22 citations
  2. 02

    Elastic Compton Scattering from 3He and the Role of the Delta

    Arman Margaryan (Duke U.) · Bruno Strandberg (U. of Glasgow and Nikhef) Harald W. Griesshammer (George Washington U.) · Judith A. McGovern (U. of Manchester) · Daniel R. Phillips (Ohio U.) · Deepshikha Shukla (Rockford U.)

    We report observables for elastic Compton scattering from He in Chiral Effective Field Theory with an explicit degree of freedom (EFT) for energies between 50 and 120 MeV. The He amplitude is complete at N3LO, , and in general converges well order by order. It includes the dominant pion-loop and two-body currents, as well as the Delta excitation in the single-nucleon amplitude. Since the cross section is two to three times that for deuterium and the spin of polarised He is predominantly carried by its constituent neutron, elastic Compton scattering promises information on both the scalar and spin polarisabilities of the neutron. We study in detail the sensitivities of 4 observables to the neutron polarisabilities: the cross section, the beam asymmetry and two double asymmetries resulting from circularly polarised photons and a longitudinally or transversely polarised target. Including the Delta enhances those asymmetries from which neutron spin polarisabilities could be extracted. We also correct previous, erroneous results at N2LO, i.e.~without an explicit Delta, and compare to the same observables on proton, neutron and deuterium targets. An interactive Mathematica notebook of our results is available from hgrie@gwu.edu.

    nucl-thhep-phEPJA(2018)·18 citations
  3. 03

    Impact of magnetic field on shear viscosity of quark matter in Nambu-Jona-Lasinio model

    Sabyasachi Ghosh🇮🇳 · Bhaswar Chatterjee🇮🇳 · Payal Mohanty🇮🇳 · Arghya Mukharjee🇮🇳 · Hiranmaya Mishra🇮🇳

    We have investigated shear viscosity of quark matter in presence of a strong uniform magnetic field background where Nambu-Jona-Lasinio model has been considered to describe the magneto-thermodynamical properties of the medium. In presence of magnetic field, shear viscosity coefficient gets split into different components because of anisotropy in tangential stress of the fluid. Four different components can be merged to two components in limit of strong field, where collisional width of quark becomes much lower than its synchrotron frequency. A simplified contact diagram of quark-quark interaction can estimate a small collisional width, where strong field limit expressions are exactly applicable. Although, for RHIC or LHC matter, one can expect a large thermal width, for which generalized four components viscosities are necessary. We have explored these all different possible cases in the thermodynamical framework of Nambu-Jona-Lasinio model.

    ↳ hep-phnucl-thPRD(2019)·37 citations

Affiliations

first authorsco-authorsvia INSPIRE