Possible collective band in neutron-rich Sn-119

Excited states of Sn-119 have been studied using an in-beam gamma-ray spectroscopic technique following the incomplete fusion of Li-7 on a Cd-116 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.