English

Competition between the neutron-proton pair break-ups delineating the level structure of 202Po

Nuclear Experiment 2025-05-16 v1 Nuclear Theory

Abstract

High-spin spectroscopic study of 202^{202}Po (ZZ = 84, NN = 118) has been carried out using the 195^{195}Pt(12^{12}C, 5n)202^{202}Po fusion-evaporation reaction. An extended level scheme has been proposed up to an excitation energy of ExE_x\approx 8 MeV and angular momentum of 27\hbar, with the addition of 57 newly observed γ\gamma-ray transitions, along with the revisions in the placement of 8 already known transitions and the multipolarities of 4 of these transitions. The energy of the unobserved 8+6+^+ \rightarrow 6^+ transition has been proposed to be 9.0(5) keV, which resolves the uncertainty in the excitation energy of the levels above the 6+^{+} state. Three new sequences of M1M1 transitions have also been identified in the high excitation energy regime and included in the proposed level scheme. The large-scale shell model calculations for Z>82Z>82 and N<126N<126 valence space have been carried out using PBPOP interaction which explained the overall level scheme for both the positive and negative parity states. The calculations successfully reproduced the purity of the proton πh9/2\pi h_{9/2} dominated 8+8^+ isomeric state, and also explained the missing E2E2 decay of the 12+{12}^+ isomeric state in terms of changing nucleonic configurations.

Keywords

Cite

@article{arxiv.2505.10237,
  title  = {Competition between the neutron-proton pair break-ups delineating the level structure of 202Po},
  author = {Sahab Singh and D. Choudhury and B. Maheshwari and R. Roy and K. Yadav and R. Palit and B. Das and P. Dey and A. Kundu and Md. S. R. Laskar and D. Negi and V. Malik and S. Jadhav and B. S. Naidu and A. V. Thomas and D. L. Balabanski and A. Dhal and S. Bhattacharya and A. K. Singh and S. Bhattacharyya and S. Nag},
  journal= {arXiv preprint arXiv:2505.10237},
  year   = {2025}
}