π-mesonic decay of the hypertriton

Abstract

The [Formula Presented]-mesonic decay of the hypertriton is calculated based on a hypertriton wave function and 3[Formula Presented] scattering states, which are rigorous solutions of three-body Faddeev equations using realistic [Formula Presented] and hyperon-nucleon interactions. The total [Formula Presented]-mesonic decay rate is found to be 101% of the free [Formula Presented] decay rate, which is close to the experimental data. Together with the nonmesonic decay the total lifetime of [Formula Presented] H is predicted to be 2.56 [Formula Presented] 10[Formula Presented] sec which is 3% smaller than for the free [Formula Presented] particle. The differential decay rate is evaluated as a function of the pion momentum. The decay into the [Formula Presented] channel is stronger than in the [Formula Presented] channel in contrast to the situation for the nonmesonic decay. The ratio for the decay rate into [Formula Presented] He + [Formula Presented] to the decay rate into all channels including [Formula Presented] is found to be 0.379, which is close to the experimental value. We visualize the decay into the dominant channel [Formula Presented] in a Dalitz plot. Finally we compare the polarization of the outgoing proton in free unpolarized [Formula Presented] decay to the polarization of [Formula Presented] He in unpolarized [Formula Presented] H decay and we compare the closely related asymmetry of [Formula Presented] emitted parallel and antiparallel with respect to the spin direction for a polarized [Formula Presented] to the corresponding asymmetry for a polarized [Formula Presented] H. © 1998 The American Physical Society.