118551278
Theoretical Studies of Rare-Earth Nuclei leading to $_{50}$Sn-Daughter Products and the Associated Shell Effects
Cluster decays of rare-earth nuclei are studied with a view to look for neutron magic shells for the $_{50}$Sn nucleus as the daughter product always. The $^{100}$Sn and $^{132}$Sn radioactivities are studied to find the most probable cluster decays and the possibility, if any, of new neutron shells. For a wide range of parent nuclei considered here (from Ba to Pt) $^{12}$C from $^{112}$Ba and $^{78}$Ni from $^{210}$Pt parent are predicted to be the most probable clusters (minimum decay half-life) referring to $^{100}$Sn and $^{132}$Sn daughters, respectively. Also, $^{22}$Mg decay of $^{122}$Sm is indicated at the second best possibilty for $^{100}$Sn-daughter decay. In addition to these well known magic shells (Z=50, N=50 and 82), a new magic shell at Z=50, N=66 ($^{116}$Sn daughter) is indicated for the $^{64}$Ni decay from $^{180}$Pt parent.
119254035
The cluster-core model for the halo structure of light nuclei at the drip lines
Nuclei at both the neutron- and proton-drip lines are studied. In the cluster?core model, the halo structure of all the observed and proposed cases of neutron- or proton-halos is investigated in terms of simple potential energy surfaces calculated as the sum of binding energies, Coulomb repulsion, nuclear proximity attraction and the centrifugal potential for all the possible cluster+core configurations of a nucleus. The clusters of neutrons and protons are taken to be unbound, with additional Coulomb energy added for proton-clusters. The model predictions agree with the available experimental studies but show some differences with the nucleon separation energy hypothesis, particularly for proton-halo nuclei. Of particular interest are the halo structures of 11N and 20Mg. The calculated potential energy surfaces are also useful to identify the new magic numbers and molecular structures in exotic nuclei. In particular, N = 6 is a possible new magic number for very neutron-deficient nuclei, but N = 2, Z = 2 and Z = 8 seem to remain magic even for such nuclei, near the drip line.
118221659
Role of Momentum Dependent Interactions in Nuclear Stopping
In the present analysis, thousand of events were simulated for the neutron rich reaction of 54Xe131 + 54Xe131, at different impact parameters using hard (HMD) and soft (SMD) momentum dependent equation of state. one can clearly see more stopping in the presence of HMD. Production of LCP's and free particles follows the same trend as stopping parameter R. This simply implies that the fragment production can act as a global indicator for the nuclear stopping.
119359448
Binary breakup: Onset of multifragmentation and vaporization in Ca-Ca collisions
The incomplete fusion, onset of multifragmentation and vaporization is studied in Ca-Ca collisions at bombarding energies between $20\char21{}1000A\mathrm{MeV}$ and at impact parameters between $b=0$ and ${b}_{\mathrm{max}}.$ The simulations of Ca-Ca are performed using the quantum molecular dynamics (QMD) model. We find incomplete fusion events at $E/A=20\char21{}30\mathrm{MeV}.$ With an increase in the bombarding energy, the multiplicity of fragments first increases to a maximum value and then decreases for central and semi-central collisions. This peak in the multiplicity of fragments shifts towards higher energies for light mass fragments compared to intermediate mass fragments. The peak in the fragment production can be related to a critical point where onset of the fragmentation starts. The light mass fragment production at a given incident energy does not show any rise and fall in the multiplicity with a change in the impact parameter. The IMF production at higher energies $(g~150A$ MeV), however, has a clear rise and fall in their multiplicity.
9833237
Measurement of the damping of the nuclear shell effect in the doubly magic 208Pb region.
The damping of the nuclear shell effect with excitation energy has been measured through an analysis of the neutron spectra following the triton transfer in the (7)Li induced reaction on (205)Tl. The measured neutron spectra demonstrate the expected large shell correction energy for the nuclei in the vicinity of doubly magic (208)Pb and a small value around (184)W. A quantitative extraction of the allowed values of the damping parameter γ, along with those for the asymptotic nuclear level density parameter ã, has been made for the first time.
120300963
Bianchi type-II space-times with constant deceleration parameter in self creation cosmology
Abstract
The properties of locally rotationally symmetric Bianchi type-II perfect fluid space-times are analyzed in Barber’s second self-creation theory by using a special law of variation for Hubble’s parameter that yields a constant value of deceleration parameter. By assuming the equation of state p=γρ, many new solutions are obtained for different era—Zel’dovich, radiation, vacuum and vacuum energy dominated. The solutions with power-law and exponential expansion are discussed. A detailed study of geometrical and physical parameters is carried out. The nature of singularity is also clarified in each case.

119175675
Study of transfer reaction channel in $^{12}$C + $^{27}$Al system
The 1p transfer channel in the $^{27}$Al($^{12}$C, $^{11}$B)$^{28}$Si reaction has been studied at E$_{lab}$ = 73, 81 and 85 MeV. The finite range distorted wave Born approximation calculations have been performed using phenomenological optical model potential to analyze the angular distributions for 3 transitions populating the 0.0, 1.78 and 4.62 MeV states of $^{28}$Si and 2 transitions populating the 2.12 and 4.44 MeV states of $^{11}$B via the $^{27}$Al($^{12}$C, $^{11}$B)$^{28}$Si reaction. The spectroscopic strengths as well as spectroscopic factors have been extracted for all the five states. The extracted strength values are compared with shell model calculations.