Abstract
We report on the experimental study of quadrupole collectivity in the neutron-deficient nucleus Sn using intermediate-energy Coulomb excitation. The value for the excitation of the first state in Sn has been measured to be b relative to the well-known value of Cd. This result disagrees by more than one sigma with a recently published measurement [G. Guastalla et al., Phys. Rev. Lett. 110, 172501 (2013)]. Our result indicates that the most modern many-body calculations remain unable to describe the enhanced collectivity below midshell in Sn approaching . We attribute the enhanced collectivity to proton particle-hole configurations beyond the necessarily limited shell-model spaces and suggest the asymmetry of the -value trend around midshell to originate from enhanced proton excitations across as is approached.
- Received 1 July 2013
DOI:https://doi.org/10.1103/PhysRevC.88.051301
©2013 American Physical Society