0000000000302988
AUTHOR
Kenji Hosomi
Status of J-PARC E07: Systematic study of double strangeness nuclei with hybrid emulsion method
J-PARC E07 is the most complex emulsion experiment to date investigating double hypernuclei with a hybrid emulsion method. This experiment aims to detect 104 Ξ− stop events, ten times more events than the past experiments. Thus, an unequivocal identification of several new double hypernuclei is expected. The beam exposure has been completed at the K1.8 beam line of the J-PARC hadron facility in June 2017. The photographic development of all emulsion sheets has also been completed in February 2018. The emulsion sheets are presently being analyzed with dedicated optical microscopes. Current statistics is comparable to that of E373 and so far 10 events of 3-vertices topology have been detected…
Observation of a Be double-Lambda hypernucleus in the J-PARC E07 experiment
A double-$\Lambda$ hypernucleus, ${}_{\Lambda\Lambda}\mathrm{Be}$, was observed by the J-PARC E07 collaboration in nuclear emulsions tagged by the $(K^{-},K^{+})$ reaction. This event was interpreted as a production and decay of $ {}_{\Lambda\Lambda}^{\;10}\mathrm{Be}$, ${}_{\Lambda\Lambda}^{\;11}\mathrm{Be}$, or ${}_{\Lambda\Lambda}^{\;12}\mathrm{Be}^{*}$ via $\Xi^{-}$ capture in ${}^{16}\mathrm{O}$. By assuming the capture in the atomic 3D state, the binding energy of two $\Lambda$ hyperons$\,$($B_{\Lambda\Lambda}$) of these double-$\Lambda$ hypernuclei are obtained to be $15.05 \pm 0.11\,\mathrm{MeV}$, $19.07 \pm 0.11\,\mathrm{MeV}$, and $13.68 \pm 0.11\,\mathrm{MeV}$, respectively. Base…
Observation of Coulomb-Assisted Nuclear Bound State of Ξ−–N14 System
In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}N→_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21 MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.