Λ 4 H formation from K − absorption at rest on 4 He, 7 Li, 9 Be, 12 C, 16 O and 40 Ca targetsformation from K − absorption at rest on 4 He, 7 Li, 9 Be, 12 C, 16 O and 40 Ca targets

Formation of Λ 4 H hypernucleus from stopped K− on4He,7Li,9Be,12C,16O and40Ca was studied by detecting π− from the two-body decay of Λ 4 H, Λ 4 H→He+π−. The formation probabilities of Λ 4 H per stopped K− on these target nuclei were measured. From the coincidence measurement with π0 and π±, we found that the Λ 4 H hyperfragment formation onA>4 nuclei cannot be accounted for by the direct reaction onα cluster,4He(K−, π0) Λ 4 H, alone.