Search for HΛ6 hypernucleus by the Li6(π−,K+) reaction at pπ−=1.2GeV/c

We have carried out an experiment to search for a neutron-rich hypernucleus, 6 H, by the 6 Li(π − , K + ) reaction at pπ− =1.2 GeV/c. The obtained missing-mass spectrum with an estimated energy resolution of 3.2 MeV (FWHM) showed no peak structure corresponding to the 6 H hypernucleus neither below nor above the 4 H+2n particle decay threshold. An upper limit of the production cross section for the bound 6 H hypernucleus was estimated to be 1.2 nb/sr at 90% confidence level.