Spectroscopic study of K 38 above the 31.67 μ s isomer

Abstract

High-spin states of K38 above the 31.67μs (τm) isomer, populated through the C12(Si28,np)K38 reaction with a 110 MeV Si28 beam, have been studied by using the Indian National Gamma Array (INGA) facility. Two new levels and four new transitions have been added to the existing level scheme. The spins and parities of most of the levels above the isomer have been assigned, modified, and confirmed from RDCO, RADO, and linear polarization measurements. The multipole mixing ratios (δ) for a few transitions have been measured. Large-basis shell-model calculations have been performed to understand the microscopic origin of these levels. In our calculations, different particle restrictions in sd- and pf-shell orbitals were used to reproduce the experimental level energies. Two-nucleon transfer spectroscopic factors have also been calculated for the levels above the isomer to support the new spin and parity assignments. Prediction of collective excitation at high excitation energy in K38 is also discussed. © 2020 American Physical Society.