Population of the2ms+mixed-symmetry state ofBa140with theα-transfe

Abstract

Background: Identification of proton-neutron mixed-symmetric one-quadrupole phonon excitations (the 2 + ms states) of atomic nuclei provides information on the isovector part of the residual nucleon-nucleon interaction. It was predicted that the 2 + ms state of particular nuclei close to the U (5) 140 Ba was populated by α transfer three times weaker than predicted. Another 2 + state that can be ruled out as the MSS was in turn as strongly populated by the α transfer as predicted for the MSS. Conclusions: The relative population of 2 + states by α-transfer cannot serve as a new signature for MSSs, since other 2 + states are also strongly populated. Nevertheless, the substantial population of the MSS candidate of 140 Ba by α transfer qualifies this type of reaction as suitable tool to excite MSSs and study their electromagnetic decay properties.