165 research outputs found
Systematics of Anti magnetic rotation in even-even Cd isotopes
The lifetimes for the high spin levels of the yrast band of Cd has
been measured. The estimated B(E2) values decrease with increase in angular
momentum. This is the characteristic of Anti magnetic rotation as reported in
Cd. However, alignment behavior of Cd is completely
different from its even-even neighbors. A model based on classical particle
plus rotor has been used to explore the underlying systematics and develop a
self consistent picture for the observed behavior of these isotopes.Comment: 18 pages including 6 figures. Accepted to be published in PLB, with
some modification in the tex
Small Quadrupole Deformation for the Dipole Bands in 112In
High spin states in In were investigated using Mo(O,
p3n) reaction at 80 MeV. The excited level have been observed up to 5.6 MeV
excitation energy and spin 20 with the level scheme showing three
dipole bands. The polarization and lifetime measurements were carried out for
the dipole bands. Tilted axis cranking model calculations were performed for
different quasi-particle configurations of this doubly odd nucleus. Comparison
of the calculations of the model with the B(M1) transition strengths of the
positive and negative parity bands firmly established their configurations.Comment: 10 pages, 11 figures, 2 table
Influence of Incomplete Fusion Reaction on Complete Fusion Below 10 Mev/ Nucleon Energies
An attempt has been made in the present work to provide an ample opportunity to explore the information about the influence of incomplete fusion (ICF) reaction dynamics on complete fusion in heavy ion induced nuclear reactions. excitation functions for several evaporation residues produced in the interaction of projectile 16O with target 175lu have been measured over the wide projectile energy range ≈ 70-100 MeV. the recoil-catcher activation technique followed by the offline γ-ray spectroscopy has been used for the present measurements. In case of precursor decay, we have made use of Cavinato et al. formulation to calculate the independent cross-section of the identified residues. the measured efs are compared with theoretical predictions of statistical model code PACE-2 and any enhancement in the measured cross-section from theoretical prediction may be due to ICF reaction process. An attempt has been made to estimate the ICf contribution of the cross-section from the measured excitation function data and the dependence of ICf cross-section on projectile energy
High-spin spectroscopy in At: Evidence of a 29/2 isomeric state
Yrast and near-yrast states above the known 25/2 isomer in At
are established for the first time. The level scheme is extended up to
47/2 and 6.5 MeV with the addition of about 60 new -ray
transitions. The half-life of the 25/2 isomer is revisited and a value of
= 107.5(9) ns is deduced. Evidence of a hitherto unobserved
29/2 isomer in At is presented. A systematic study of
values for the transitions de-exciting the 29/2 isomer in the neighboring
odd- At isotopes suggests a half-life in the 24 s range for this
state in At. The experimental results are compared with large-scale
shell-model calculations performed using the KHM3Y effective interaction in the
= 50126, = 82184 model space and an overall good agreement is
noted between the theory and the experiment. A qualitative comparison of the
excited states and the isomers with analogous states in neighboring nuclei
provides further insight into the structure of At.Comment: 15 pages, 13 figure
Coexisting single-particle excitations and octupole correlations in transitional nucleus
The level structure of the transitional nucleus has been
extended with the addition of around 20 new transitions. The discrepancies
between the placements of several transitions reported in the earlier studies
are resolved. The newly-established negative-parity sequence at low excitation
energies hints at the expected parity-doublet structures in this nucleus. The
properties of the observed simplex bands are compared with that of similar
bands in neighboring nuclei. Since the presence of parity-doublet structures
reflect octupole correlations, theoretical calculations using
reflection-asymmetric triaxial particle rotor model (RAT-PRM) have been
performed. A comparison of the observed features of the simplex bands with the
predictions of the RAT-PRM calculations suggests that
exhibits an intermediate the behavior between the extremes of spherical and
octupole-deformed nuclei. The termination of the simplex bands at intermediate
energies and the structures lying above reflect the dominance of the
single-particle excitations at higher excitation energies.Comment: 15 pages, 16 figure
Projectile Break-up Effect on Fusion in 16O + 156Gd Reaction at Energy Range 4.3-6.3 MeV/A
103-108We discuss our present understanding of the incomplete fusion (ICF) reaction dynamics, the excitation function of six evaporation residues (ERs) have been measured in 16O + 156Gd reaction at projectile energy range, E/A ~ 4.3-6.3 MeV/Nucleon. Some of the ERs are produced directly & indirectly (i.e. through pre-cursor), the pre-cursor contributions have been separated out from the measured cumulative cross-section with the help of Cavinato et al.1. After correcting the pre-cursor contribution, the independent yield has been compared with the statistical model code PACE-22, which describes the fusion reaction cross section. In order to optimize the parameter of the code PACE-2 that reproduces the cross section of all the complete fusion (CF) channels like xn and /or pxn-channels. Using the same set of input parameters, cross section of the ERs populated via incomplete fusion (ICF) channels have been measured. The enhancement in the measured cross section of the ERs populated via ICF channels over the PACE-2 prediction have been measured, which indicates the occurrence of the break-up of projectile 16O into (12C+α) and/or (8Be+2α) leading to ICF reaction dynamics
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