Ab initio calculation of the β decay from 11Be to a 10Be + p resonance

The exotic beta-delayed proton emission is calculated in Be-11 from first principles using chiral two- and three- nucleon forces. To investigate the unexpectedly large branching ratio measured in Ayyad et al. [Phys. Rev. Lett. 123, 082501 (2019)], we calculate the proposed (1/2(+), 1/2) proton resonance in B-11 using the no-core shell model with continuum. This calculation helps to address whether this enhancement is caused by unknown dark decay modes or an unobserved proton resonance. We report a branching ratio of b(p) = (1.3 +/- 0.5) x 10(-6), suggesting that its unexpectedly large value is caused by an unobserved proton resonance in B-11.

Automated summary

The exotic beta-delayed proton emission in Be-11 is calculated using chiral two- and three-nucleon forces. The study investigates the unexpectedly large branching ratio measured in previous research by calculating the proposed proton resonance in B-11. The results suggest that the large value of the branching ratio is caused by an unobserved proton resonance.