arXiv subjects

C. R. Praharaj

Publications and source records attributed to C. R. Praharaj.

6 recordsLinked to original sources

arXiv2019

Microscopic study of K-Selection Rule Violation in $^{182}$W K=10$^+$ Isomer Decay

In this paper we study the microscopic mechanism for the retarded decay of K-isomers to lower K bands. We do angular momentum projection from suitable intrinsic states. The retardation arises from poor overlap between the low K and high K bands in the integral over Euler angles. Deformed HF and angular momentum projection calculations are done for the decay of the $K=10^+$ isomer band to the ground band of $^{182}W$. K-mixing is unimportant and the K quantum numbers of the bands are quite good. There is significant difference in the reduced matrix elements of transition operators in our formalism and that in the rotational model. Angular momentum projection gives J-selection rule but there is no K selection rule for reduced matrix elements of electromagnetic multipole operators. Thus, E2 and M1 transitions from the K isomer to the ground band of $^{182}W$ are finite but retarded in angular momentum projection theory, as in experiments. This provides a theoretical basis for the study of K-isomers and their decay modes. Quantitative results are presented. The microscopic model gives J-selection rule and angular momentum conservation for combined matter and radiation systems.

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arXiv2018

Systematic study of high-K isomers in the midshell Gd and Dy nuclei

High-K isomers are well known in the rare-earth region and provide unique access to the high spin structures of the nuclei. With the current interest in the study of neutron-rich rare-earth nuclei at Radioactive Ion Beam (RIB) facilities, we present here theoretical results of the band structures of neutron-rich Gd and Dy nuclei, including the high K-isomers. Apart from the already known K-isomers, we predict some more K-isomers and these are suggested for future studies at RIB facilities. Self-consistent Deformed Hartree-Fock and Angular Momentum Projection theories are used to get the intrinsic structures, band-spectra and electromagnetic transitions probabilities of the ground band as well as bands based on isomers.

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arXiv2014

Superdeformed structures and low $Ω$ parity doublet in Ne$-$S nuclei near neutron drip-line

The structure of Ne, Na, Mg, Al, Si, P and S nuclei near the neutron drip-line region is investigated in the frame-work of relativistic mean field theory and non-relativistic Skyrme Hartree-Fock formalism. The recently discovered nuclei $^{40}$Mg and $^{42}$Al, which are beyond the drip-line predicted by various mass formulae are located within these models. We find many largely deformed neutron-rich nuclei, whose structures are analyzed. From the structure anatomy, we find that at large deformation, low $Ω$ orbits of opposite parities (e.g. $\frac{1}{2}^+$ and $\frac{1}{2}^-$) occur close to each other in energy.

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arXiv2011

Study of Energy Spectra and Electromagnetic moments of Double Beta Decay Nuclei in Deformed Hartree-Fock Model

Spectroscopy of nuclei in the mass range A=76 to A=130, participating in double beta decay processes are studied in the framework of the self-consistent deformed Hartree-Fock (HF) and angular momentum (J) projection model. Spectra of ground bands have been studied and compared with available experimental results for even-even parent and daughter as well as for intermediate odd-odd nuclei. To test the reliability of the wave functions we have also calculated the reduced E2 transition matrix elements, electric quadrupole moments and magnetic dipole moments for these nuclei. The calculated results are compared with the experimental findings and substantial agreement is achieved.

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arXiv2011

Rotational Bands and Electromagnetic Transitions of some even-even Neodymium Nuclei in J-Projected Hartree-Fock Model

Rotational structures of even-even $^{148-160}$Nd nuclei are studied with the self-consistent deformed Hartree-Fock (HF) and angular momentum (J) projection model. Spectra of ground band, recently observed $K=4^{-}$, $K=5^{-}$ and a few more excited, positive and negative parity bands have been studied upto high spin values. Apart from these detailed electromagnetic properties (like E2, M1 matrix elements) of all the bands have been obtained. There is substantial agreement between our model calculations and available experimental data. Predictions are made about the band structures and electromagnetic properties of these nuclei. Some 4-qasiparticle K-isomeric bands and their electromagnetic properties are predicted.

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arXiv2010

Large deformed structures in Ne-S nuclei near neutron drip-line

The structure of Ne, Na, Mg, Al, Si and S nuclei near the neutron drip-line region is investigated in the frame-work of relativistic meannfield (RMF) and non-relativistic Skyrme Hartree-Fock formalisms. The drip-line of these nuclei are pointed out. We analysed the large deformation structures and many of these neutron rich nuclei are quite deformed. New magic number are seen for these deformed nuclei.

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