Abstract
We present a novel technique for studying the quenching of shell gaps in exotic isotopes. The method is based on extracting Gamow-Teller (, ) transition strengths [] to low-lying states from charge-exchange reactions at intermediate beam energies. These Gamow-Teller strengths are very sensitive to configuration mixing between cross-shell orbitals, and this technique thus provides an important complement to other tools currently used to study cross-shell mixing. This work focuses on the shell gap. We populated the ground and 2.24 MeV states in using the (, ) reaction at in inverse kinematics. Using the ground-state value from -decay measurements () as a calibration, the for the transition to the second state was determined to be . Comparing the extracted Gamow-Teller strengths with shell-model calculations, it was determined that the wave functions of the first and second states in are composed of and configurations, respectively.
- Received 18 November 2011
DOI:https://doi.org/10.1103/PhysRevLett.108.122501
© 2012 American Physical Society