Evidence for the First Excited State of ^{7}H.

Abstract

The ^{7}H system was populated in the ^{2}H(^{8}He,^{3}He)^{7}H reaction with a 26AMeV ^{8}He beam. The ^{7}H missing mass energy spectrum, the ^{3}H energy and angular distributions in the ^{7}H decay frame were reconstructed. The ^{7}H missing mass spectrum shows a peak, which can be interpreted either as unresolved 5/2^{+} and 3/2^{+} doublet or one of these states at 6.5(5)MeV. The data also provide indications of the 1/2^{+} ground state of ^{7}H located at 1.8(5)MeV with quite a low population cross section of ∼25 μb/sr within angular range θ_{c.m.}≃(17°-27°).