arXiv subjects

Shashi K Dhiman

Publications and source records attributed to Shashi K Dhiman.

3 recordsLinked to original sources

arXiv2020

Microscopic study of the Shell Structure evolution in isotopes of light to middle mass range Nuclides

The shell structure of even-even isotopes in Si, S, Ar and Ca has been analysed. The theoretical calculations of shell closure parameter $D_{n} (N)$ and the differential variation of the two-neutron separation energy $dS_{2n} (Z, N )$ are carried out within the framework of Hartree-Fock-Bogoliubov theory. Calculations are carried out for different skyrme forces and their sensitivity has been tested. Same nuclides are studied by employing the relativistic mean field aproach based on meson exchange and point coupling models. Theoretically calculated estimates are in good agreement with the recently available experimental data which fortifies signature of shell closure at N = 14 and 20 in case of Si, N = 14, 20 and 28 in S and N=20 and 28 in Ar and Ca isotopes.

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arXiv2019

Structural Properties of Rotating Hybrid Compact Stars with Color-Flavour-Locked Quarks Matter core and its Tidal Deformability

We investigate the possible sequels, for the hybrid compact stars consisting of nucleons, hyperons and three flavour color-flavor-locked quarks phase under global neutrality and chemical equilibrium conditions. The hadron equations of state are computed within the framework of energy density functionals based on the relativistic mean field theory by employing two different model parameterizations. The quarks matter phase of equation of state is computed by using Quarks Quasiparticle model derived from a non-relativistic energy density-functional approach. A plausible set of hybrid equations of state for superdense hadron-quarks matter is obtained and, which satisfies the constraints provided by bulk nuclear matter, the observational data of frequencies and maximum Gravitational mass 2$M_\odot$ with their extracted radii, Keplerian limits, secular axisymmetric instability and limits of tidal deformabilities from GW170817 binary neutron stars (BNS) merger. We obtained structural properties of nonrotating and rotating compact stars, the evolutionary sequences with constant baryonic mass star spinning down by electromagnetic and gravitational radiations and, discuss the issues relating to phase transition from hadrons to quarks matter phase. The internal structure of rotating star with observed spin down frequencies, exhibiting shrinkage of soft quarks core of compact stars are discussed for constant baryonic mass. We present the theoretically computed limits of radii for the spin down configurations of hybrid stars corresponding to the recently observed millisecond pulsars. We also present and discuss the calculated results for tidal deformability, $Λ$ and tidal parameters $Λ_1$, $Λ_2$ of non spining hybrid star which are consistent with the waveform model analysis of GW170817 BNS.

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arXiv2019

A Study of Charge Radii and Neutron Skin Thickness near Nuclear Drip Lines

We studied the charge radius, rms radius and neutron skin thickness $Δr_{np}$ in even-even isotopes of Si, S, Ar and Ca and isotones of N =20, 28, 50 and 82. The $Δr_{np}$ in doubly-magic $^{48}$Ca, $^{68}$Ni, $^{120,132}$Sn and $^{208}$Pb nuclei has also been calculated. Theoretical calculations are done with the Hartree-Fock-Bogoliubov theory with the effective Skyrme interactions. Calculated theoretical estimates are in good agreement with the recently available experimental data. The charge radii for Si, S, Ar and Ca isotopes is observed to be minimum at neutron number N =14. The theoretically computed results with UNEDF0 model parameterization of functional are reasonably reproducing the experimental data for $Δr_{np}$ in $^{48}$Ca, $^{68}$Ni and $^{120,132}$Sn. The energy density functional of UNEDF1 model provides much improved result of $Δr_{np}$ for $^{208}$Pb.

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