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Nuclear Theory·nucl-th

Tuesday·September 12, 2017

12 papers—5 primary·7 cross-listed

All12Primary5Cross-lists7
  1. 01

    Emergence of a Brunnian neutron state

    Johannes Kirscher

    We discuss a quantum-statistical feature of non-relativistic identical fermions whose interaction is predominantly attractive at low energies. Specifically, we consider exotic, multi-neutron nuclei. From the enhancement of an arbitrarily small P-wave interaction between two nucleons, we infer the existence of a particle-stable nucleus composed entirely of neutrons. While we cannot specify the number of neutrons in the system, we predict that none of its substructures is bound. The independence of this deduction from the short-distance structure of the nuclear interaction and its consistency with deuteron, triton, and helium-4 properties is established.

    nucl-thnucl-ex4 citations
  2. 02

    Shear viscosity of a pion gas due to and interactions

    Sabyasachi Ghosh🇧🇷 · Gastao Krein🇧🇷 · Saurav Sarkar🇮🇳

    We have calculated the shear viscosity of pion medium, where propagating pion has some finite thermal width due to interaction with the low mass resonances, and . With the help of standard thermal field theoretical technique, the thermal width of the pion has been calculated from the pion self-energy diagram for and loops, where an effective Lagrangian density has been used for interaction part. We have found a very small value of shear viscosity by entropy density ratio (), which is very close to the KSS bound.

    nucl-thhep-phPoS(2017)·0 citations
  3. 03

    Cluster and toroidal aspects of isoscalar dipole excitations in C

    Yoshiko Kanada-En'yo · Yuki Shikata · Horiyuki Morita

    We investigated cluster and toroidal aspects of isoscalar dipole excitations in C based on the shifted basis antisymmetrized molecular dynamics combined with the generator coordinate method, which can describes 1p-1h excitations and dynamics. In the MeV region, we found two low-energy dipole modes separating from the giant dipole resonance. One is the developed -cluster state and the other is the toroidal dipole mode. The cluster state is characterized by the large amplitude cluster motion beyond the 1p-1h model space, whereas the toroidal dipole mode is predominantly described by 1p-1h excitations on the ground state. The low-energy dipole states are remarkably excited by the toroidal dipole operator, which can measure the nuclear vorticity. For compressive dipole transition strengths, a major part is distributed in the MeV region for the giant dipole resonance, and 5\% of the total energy weighted sum exist in the MeV region.

    nucl-thPRC(2018)·16 citations
  4. 04

    Mass-15 nuclei and predicting narrow states beyond the proton drip line

    P. R. Fraser · K. Amos · L. Canton · S. Karataglidis · D. van der Knijff · J. P. Svenne

    In a previous letter (Phys. Rev. Lett. 96, 072502 (2006)), the multi-channel algebraic scattering (MCAS) technique was used to calculate spectral properties for proton-unstable F and its mirror, C. MCAS achieved a close match to the then-new data for O elastic scattering and predicted several unusually narrow resonances at higher energies. Subsequently, such narrow resonance states were found. New cross section data has been published characterising the shape of the resonance. Herein we update that first MCAS analysis and its predictions. We also study the spectra of the set of mass-15 isobars, C, N, O, and F, using the MCAS method and seeking a consistent Hamiltonian for clusterisation with a neutron and a proton, separately, coupled to core nuclei C and O.

    nucl-thPRC(2019)·7 citations
  5. 05

    Excitation energy shift and size difference of low-energy levels in -shell hypernuclei

    Yoshiko Kanada-En'yo🇯🇵

    We investigated structures of low-lying -orbit states in -shell hypernuclei () by applying microscopic cluster models for nuclear structure and a single-channel folding potential model for a particle. For systems, the size reduction of core nuclei is small, and the core polarization effect is regarded as a higher-order perturbation in the binding. The present calculation qualitatively describes the systematic trend of experimental data for excitation energy change from to , in systems. The energy change shows a clear correlation with the nuclear size difference between the ground and excited states. In and , the significant shrinkage of cluster structures occurs consistently with the prediction of other calculations.

    nucl-thPRC(2018)·12 citations

Affiliations

first authorsco-authorsvia INSPIRE