Search for 6ΛH hypernucleus by the (π-, K+) reaction at pπ-=1.2GeV/c

The study of neutron-rich hypernuclei is one of the most important topics in the strangeness nuclear physics. The glue-like role of the Λ hyperon is expected to be critical in nuclei beyond the neutron-drip line. The knowledge of the behavior of hyperons in a neutron-excess environment will significantly affect our understanding of neutron stars because the addition of hyperons softens the Equation of State of matter at the core. To study its effects, we selected the 6ΛH hypernucleus which consists of one proton, four neutrons, and one Λ hyperon. Theoretical calculations of binding energy of 6ΛH were performed with several models, and these mass differences were more than 3MeV. Therefore, it is important to measure the Λ binding energy experimentally. On the other hand, theoretical calculation of production cross section cannot be investigated because production mechanisms of neutron-rich hypernuclei ar