Formation ofHΛ4hypernuclei fromK−absorption at rest on light nuclei

Formation of ${}_{\Lambda }{}^4{}_{}{}^{}\mathrm{H}$ hypernuclei from $K^{-}$ absorption at rest on light nuclear targets was studied by measuring monochromatic ${\pi }^{-}\text{'}\mathrm{s}$ from the two-body decay, ${}_{\Lambda }{}^4{}_{}{}^{}\mathrm{H}\to {}_{}{}^4{}_{}{}^{}\mathrm{He}+{\pi }^{-}$. The formation probabilities of ${}_{\Lambda }{}^4{}_{}{}^{}\mathrm{H}$ from ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ targets were extracted to be (0.74±0.10)×${10}^{-2\mathrm{}}$, (3.0±0.4)×${10}^{-2\mathrm{}}$, (1.57±0.18)×${10}^{-2\mathrm{}}$, (1.00±0.14)×${10}^{-2\mathrm{}}$, and (0.47±0.08)×${10}^{-2\mathrm{}}$ per stopped $K^{-}$, respectively. Possible mechanisms for the production of ${}_{\Lambda }{}^4{}_{}{}^{}\mathrm{H}$ are discussed.