Σ hypernuclear states in (K−, π±) reactions on 12C

Abstract Using negative kaons of momenta 400 and 450 MeV/ c , Σ hypernuclear states have been produced in (K − , π − ) and (K − , π + ) reactions on 12 C. The observed states are interpreted as the recoilless production of Σ particles on carbon. The upper limit for the widths of these states is estimated to be 5 MeV, independent of the charge of the Σ particle.