Evidence of a new state in ${}^{11}$Be observed in the ${}^{11}$Li $\beta$-decay

Abstract

Coincidences between charged particles emitted in the $\beta$-decay of ${}^{11}$Li were observed using highly segmented detectors. The breakup channels involving three particles were studied in full kinematics allowing for the reconstruction of the excitation energy of the ${}^{11}$Be states participating in the decay. In particular, the contribution of a previously unobserved state at 16.3 MeV in ${}^{11}$Be has been identified selecting the $\alpha$ + ${}^7$He$\to \alpha$ + ${}^6$He+n channel. The angular correlations between the $\alpha$ particle and the center of mass of the ${}^6$He+n system favors spin and parity assignment of 3/2${}^{-}$ for this state as well as for the previously known state at 18 MeV.

13 pages, 6 figures

References in corpus (1)

• Study of beta-delayed 3-body and 5-body breakup channels observed in the decay of ^11Li