Recent progress on hypernuclei

Abstract

Some of last year's progress made in hypernuclear physics is reviewed as follows: (i) resolving the $_{\Lambda}^5$He overbinding problem in single-$\Lambda$ hypernuclei [1]; (ii) arguing that the onset of binding double-$\Lambda$ hypernuclei is most likely at $A$=5, with the neutral systems $_{\Lambda\Lambda}^{\,\,3}$n and $_{\Lambda\Lambda}^{\,\,4}$n unbound by a large margin [2]; and (iii) revising the calculated value of the loosely bound $_{\Lambda}^3$H lifetime to a level of $\sim$20% shorter than the free $\Lambda$ lifetime [3], given recent claims from relativistic heavy ion experiments that $\tau(_{\Lambda}^3$H) is shorter than $\tau_{\Lambda}$ by as much as $\approx$(30$\pm$8)%. Also discussed briefly in this context is the lifetime expected for the questionable $_{\Lambda}^3$n hypernucleus.