1. Department of Physics, H. P. University, Shimla 171005, India
2. University Institute of Natural Sciences and Interface Technologies, Himachal Pradesh Technical University, Hamirpur 177001, India
3. Theory Division, Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata - 700064, India
4. Physics Department, Indian Institute of Technology, Roorkee, India