Experimental investigation of high-spin states in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Zr</mml:mi><mml:mprescripts/><mml:none/><mml:mn>90</mml:mn></mml:mmultiscripts></mml:math>
P. Dey, D. Negi, R. Palit, P. C. Srivastava, Md. S. R. Laskar, B. Das, F. S. Babra, S. Bhattacharya, Biswajit Das, K. Rojeeta Devi, Rolando Guibert Gala, U. Garg, S. S. Ghugre, E. Ideguchi, Suresh Kumar, A. Kundu, G. Mukherjee, S. Muralithar, Somnath Nag, S. Nandi, Neelam Neelam, M. Kumar Raja, R. Raut, Rajkumar Santra, Anupriya Sharma, S. Sihotra, A. K. Singh, R. P. Singh, T. Trivedi
Abstract
High-spin states of $^{90}\mathrm{Zr}$ have been investigated using the heavy-ion fusion-evaporation reaction $^{82}\mathrm{Se}(^{13}\mathrm{C},5n)$ at a beam energy of 60 MeV. Excited levels of $^{90}\mathrm{Zr}$ have been observed up to an excitation energy of $\ensuremath{\approx}13$ MeV and a spin of $\ensuremath{\approx}20\ensuremath{\hbar}$ with the addition of thirty-two new $\ensuremath{\gamma}$-ray transitions to the proposed level scheme. Structures of both the positive- and negative-parity states up to the highest observed spin have been interpreted with shell-model calculations using the GWBXG interaction and a $^{68}\mathrm{Ni}$ core. Calculations suggest the role of neutron excitations across the $N=50$ shell gap for states with greater than 7 MeV excitation energy. High-spin states in these bands are interpreted to be generated by the recoupling of stretched proton and neutron configurations.