Statistical double $\Lambda$ hypernuclear formation from $\Xi^-$ absorption at rest in light nuclei

TL;DR

This study models the formation of double Lambda hypernuclei from Xi-minus absorption in light nuclei, analyzing how target type and bond energy influence formation probabilities, aligning with experimental observations.

Contribution

It introduces a statistical decay model for double Lambda hypernuclear formation from Xi-minus absorption, providing predictions consistent with experimental data.

Findings

Formation probabilities vary with target nucleus and bond energy.

Predicted formation of specific hypernuclei matches experimental observations.

Small formation probability for certain hypernuclei like $^{11}_{\Lambda\Lambda}\mathrm{Be}$.

Abstract

We investigate double $\Lambda$ hyperfragment formation from the statistical decay of double $\Lambda$ compound nuclei produced in the $\Xi^-$ absorption at rest in light nuclei, $^{12}\mathrm{C}$, $^{14}\mathrm{N}$ and $^{16}\mathrm{O}$. We examine the target and the $\Lambda\Lambda$ bond energy dependence of the double $\Lambda$ hyperfragment formation probabilities, especially of those double hypernuclei observed in experiments. For the $^{12}\mathrm{C}$ ($^{14}\mathrm{N}$) target, the formation probabilities of $^{6}_{\Lambda\Lambda}\mathrm{He}$ and $^{10}_{\Lambda\Lambda}\mathrm{Be}$ ($^{13}_{\Lambda\Lambda}\mathrm{B}$) are found to be reasonably large as they are observed in the KEK-E373 (KEK-E176) experiment. By comparison, for $^{16}\mathrm{O}$ target, the formation probability of $^{11}_{\Lambda\Lambda}\mathrm{Be}$ is calculated to be small with $\Delta B_{\Lambda\Lambda}$ consistent with the Nagara event. We also evaluate the formation probability of ${}^{5}_{\Lambda\Lambda}\mathrm{H}$ from a $\Xi^-$-${}^{6}\mathrm{He}$ bound state, ${}^{7}_{\Xi}\mathrm{H}$.