Possible collective band in neutron-rich 119Sn * *Partly supported by the Major Program of Natural Science Foundation of Shandong Province (ZR2020ZD30), the National Natural Science Foundation of China (12075137, 12075138, 11975315, U1867210, U1932209), and the Young Scholars Program of Shandong University

Abstract

Excited states of 119Sn have been studied using an in-beam γ-ray spectroscopic technique following the incomplete fusion of 7Li on a 116Cd target at a beam energy of 42 MeV. A new bandlike structure is proposed to result from deformed two-particle-two-hole (2p-2h) proton excitations across the Z = 50 closed shell based on the systematics of odd-A Sn isotopes and configuration-fixed constrained triaxial relativistic mean-field calculations. This observation extends the boundaries of the deformed 2p-2h collective band to A = 119 in Sn isotopes.