Level Statistics of SU(3)↔SU(3)Transitional Region

Level statistics oftransitional region of SU(3)↔SU(3) interacting boson model is described with emphasis on the nearest neighbor spacing distributions. The energy levels of transitional Hamiltonian are calculated via the SO(6) representation of eigenstates. By employing the MLE technique, the parameter of Abul-Magd distribution is estimated which suggests less regular dynamics for transitional region as compared to dynamical symmetry limits. Also, the O(6) dynamical symmetry which is known as the critical point of this transitional region, describes a deviation to more regular dynamics. 

Keywords:- Shape Phase Transition; Interacting Boson Model (IBM); Spectral Statistics; Maximum Likelihood Estimation (MLE). 

Authors:- H. Sabri P. Hossein Nezhade Gavifekr, Z. Ranjbar, N. Fouladi1 

Department of Nuclear Physics, University of Tabriz, Tabriz-51664, Iran.
Email:- h-sabri@tabrizu.ac.ir

M. A. Jafarizadeh 

Department of Theoretical Physics and Astrophysics, University of Tabriz, Tabriz-51664, Iran.
Research Institute for Fundamental Sciences, Tabriz-51664, Iran.

http://jnp.chitkara.edu.in//pdf/papers/05_JNPMSRA_Sabri.pdf

Fission in Rapidly Rotating Nuclei

We study the effect of rotation in fission of the atomic nucleus ²⁵⁶Fm using an independent-particle shell model with the mean field represented by a deformed Woods-Saxon potential and the shapes defined through the Cassinian oval parametrization. The variations of barrier height with increasing angular momentum, appearance of double hump in fission path are analysed. Our calculations explain the appearance of double hump in fission path of 256Fm nucleus. The second minimum vanishes with increase in angular momentum which hints that the fission barrier disappears at large spin. 

Keywords:- Fission, Cassinian ovals, Rotating nuclei 

Authors:- A. K. Rhine Kumar and Vinay Suram 

Department of Physics, Indian Institute of Technology Roorkee-247667, Uttarakhand, India

http://jnp.chitkara.edu.in//pdf/papers/04_JNPMSRA_Rhine.pdf

On the Fusion of Neutron/ Proton-Rich Colliding Nuclei Using Isospin-Dependent Potentials

By using different isospin dependent proximity-type potentials, we performed a detailed study of neutron/proton-rich colliding nuclei with N/Z ratio between 0.5 and 2.0. Isotopes of three different series namely, Ne-Ne, Ca-Ca, and Zr-Zr are taken into account. A monotonous increase (decrease) in the fusion barrier positions (heights) using a unified second order nonlinear parametrization in the normalized fusion barrier positions and heights with N( Z −1) is presented. These predictions are in good agreement with the available theoretical as well as experimental results. The fusion probabilities, however shows linear dependence. Further, the neutron/proton content plays dominant role at near barrier energies only. Our results are also independent of the model used as well as reaction partner and isospin content. More experiments are needed to verify our predictions. 

Keywords: Heavy-ion fusion reaction, proximity potential, fusion barriers and cross sections. 
Authors:- Ishwar Dutt

School of Applied Sciences, Chitkara University, Himachal Pradesh-174 103, India.
Department of Physics, Panjab University, Chandigarh-160014, India.
Email:- ishwar.dutt1@chitkarauniversity.edu.in

Maninder Kaur
Department of Physics, Panjab University, Chandigarh-160014, India.

On the Fusion of Neutron/ Proton-Rich Colliding Nuclei Using Isospin-Dependent Potentials

By using different isospin dependent proximity-type potentials, we performed a detailed study of neutron/proton-rich colliding nuclei with N/Z ratio between 0.5 and 2.0. Isotopes of three different series namely, Ne-Ne, Ca-Ca, and Zr-Zr are taken into account. A monotonous increase (decrease) in the fusion barrier positions (heights) using a unified second order nonlinear parametrization in the normalized fusion barrier positions and heights with N( Z −1) is presented. These predictions are in good agreement with the available theoretical as well as experimental results. The fusion probabilities, however shows linear dependence. Further, the neutron/proton content plays dominant role at near barrier energies only. Our results are also independent of the model used as well as reaction partner and isospin content. More experiments are needed to verify our predictions. 

Keywords: Heavy-ion fusion reaction, proximity potential, fusion barriers and cross sections. 
Authors:- Ishwar Dutt

School of Applied Sciences, Chitkara University, Himachal Pradesh-174 103, India.
Department of Physics, Panjab University, Chandigarh-160014, India.
Email:- ishwar.dutt1@chitkarauniversity.edu.in

Maninder Kaur
Department of Physics, Panjab University, Chandigarh-160014, India.

Probable Projectile-Target Combinations for the Synthesis of Super Heavy Nucleus 286112

The fusion cross sections for the reactions of all the projectile-target combinations found in the cold valleys of 286112 have been studied using scattering potential as the sum of Coulomb and proximity potential, so as to predict the most probable projectile-target combinations in heavy ion fusion reactions for the synthesis of super heavy nucleus 286112. While considering the nature of potential pockets and half lives of the colliding nuclei, the systems ⁸²Ge + ²⁰⁴Hg, ⁸⁰Ge + ²⁰⁶Hg and⁷⁸Zn + ²⁰⁸Pb found in the deep cold valley region and the systems ⁴⁸Ca+²³⁸U, ³⁸S+²⁴⁸Cm and ⁴⁴Ar+²⁴²Pu in the cold valleys are predicted to be the better optimal projectile-target combinations for the synthesis of super heavy nucleus ²⁸⁶112. 

Keywords:-Heavy-ion reactions; Coulomb and proximity potential 

Authors:- K. P. Santhosh and V. Bobby Jose

School of Pure and Applied Physics, Kannur University, Swami Anandatheertha Campus,Payyanur, 670327, India.
Email :- drkpsanthosh@gmail.com

Extensions of Natural Radioactivity to 4th-Type and of the Periodic Table to Super-heavy Nuclei: Contribution of Raj K Gupta to Cold Nuclear Phenomena

We have studied here the contribution of Indian Scientists associated with Prof. Raj K. Gupta to cold nuclear phenomena during the last almost four decades, which led to the discovery of fourth kind of natural radioactivity (also known as Cluster Radioactivity, CR) and to the extension of periodic table to super heavy nuclei. It is exclusively pointed out how the Quantum Mechanical Fragmentation Theory (QMFT) advanced by Prof. Raj K. Gupta and Collaborators led to the discovery of unique phenomenon of CR along with the predictions leading to the synthesis of super heavy elements. We have also mentioned the development of dynamical theories based on QMFT, the Preformed Cluster Model(PCM) and the dynamical cluster-decay model (DCM), to study the ground and excited state decays of nuclei, respectively, by Gupta and Collaborators. It is matter of great honor and pride for us to bring out this study to enthuse the young researchers to come up with novel ideas and have inspiration from the scientific contributions of Prof. Raj K. Gupta who is coincidentally celebrating his platinum jubilee birthday anniversary this year. 

Keywords:- Cluster model, low energy, super heavy elements, alpha decay 

Authors:- BirBikram Singh

Department of Physics, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, INDIA
Email:-birbikram.singh@gmail.com

Manoj K. Sharma
School of Physics and Materials Science, Thapar University, Patiala-147004, INDIA

S. K. Patra 
Institute of Physics, Sachivalaya Marg, Bhubaneswar-751005, INDIA