Second T = 3/2 state in 9B and the isobaric multiplet mass equation
CITATION: Mukwevho, N. J., et al. 2018. Second T = 3/2 state in 9B and the isobaric multiplet mass equation. Physical Review C, 98(5):051302, doi:10.1103/PhysRevC.98.051302.
The original publication is available at https://journals.aps.org/prc
Recent high-precision mass measurements and shell-model calculations [M. Brodeur et al., Phys. Rev. Lett. 108, 212501 (2012)] have challenged a longstanding explanation for the requirement of a cubic isobaric multiplet mass equation for the lowest A=9 isospin quartet. The conclusions relied upon the choice of the excitation energy for the second T=3/2 state in 9B, which had two conflicting measurements prior to this work. We remeasured the energy of the state using the 9Be(3He,t) reaction and significantly disagree with the most recent measurement. Our result supports the contention that continuum coupling in the most proton-rich member of the quartet is not the predominant reason for the large cubic term required for A=9 nuclei.