Nanosession: Advanced Spectroscopy and Scattering

Observation of Coulomb-assisted nuclear bound state of $��^-$-$^{14}$N system

In an emulsion-counter hybrid experiment performed at J-PARC, a $��^-$ absorption event was observed which decayed into twin single-$��$ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as $��^{-} + ^{14}$N$\ \rightarrow\ ^{10}_��$Be + $^5_��$He. For the binding energy of the $��^{-}$ hyperon in the $��^-$-$^{14}$N system a value of $1.27 \pm 0.21$ MeV was deduced. The energy level of $��^-$ is likely a nuclear $1p$ state which indicates a weak $��N$-$����$ coupling.

Observation of Coulomb-assisted nuclear bound state of $\Xi^-$-$^{14}$N system

In an emulsion-counter hybrid experiment performed at J-PARC, a $\Xi^-$ absorption event was observed which decayed into twin single-$\Lambda$ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as $\Xi^{-} + ^{14}$N$\ \rightarrow\ ^{10}_\Lambda$Be + $^5_\Lambda$He. For the binding energy of the $\Xi^{-}$ hyperon in the $\Xi^-$-$^{14}$N system a value of $1.27 \pm 0.21$ MeV was deduced. The energy level of $\Xi^-$ is likely a nuclear $1p$ state which indicates a weak ${\Xi}N$-$\Lambda\Lambda$ coupling.