Search for an S-wave Resonance in ⁷Li just Above the Proton Decay Threshold

Near threshold resonances play an outsized role in nucleosynthesis and applied nuclear science. The study of nuclei removed from stability has greatly extended the list of resonances very close to decay thresholds. The No Core Shell Model with Continuum (NCSMC) recently predicted an S-wave resonance just above the proton decay threshold of ⁷Li at an excitation energy of 10 MeV [1]. The ⁶He(d,n)⁷Li reaction was employed at the Cyclotron Institute at Texas A&M to selectively populate this resonance where 4 ΔE-E [Si-Si] telescopes were used to detect and identify the ⁶He+p fragments. For this experiment, the detector design, constraints, and setup are examined as well as some early invariant-mass results. This case of a near-threshold resonance is unique because it is not important for an astrophysical reaction pathway. It is only dependent on the quantum mechanics of the ⁶He+p fragments extended into the continuum.

[1] M. Vorabbi, el al., Phys. Rev. C 100, 024304 (2019).