K. Nakazawa

γ-ray spectroscopy in Λ hypernuclei

Abstract The present status of hypernuclear γ -ray spectroscopy with Hyperball is summarized. We observed two γ transitions of 16 Λ O( 1 − → 1 − , 0 − ) and obtained the strength of the ΛN tensor force. In 10 B( K − , π − γ ) data, we did not observe the spin-flip M1 transition of 10 Λ B( 2 − → 1 − ), but γ rays from hyperfragments such as 7 Λ Li( 7 / 2 + → 5 / 2 + ) and 9 Λ Be( 3 / 2 + → 1 / 2 + ) were observed. In 11 B( π + , K + γ ) data, we observed six γ transitions of 11 Λ B. We also attempted an inclusive γ -ray measurement with a stopped K − beam.

Production of a twin single hypernuclei and the Ξ−-nuclear interaction

Abstract An event accompanied by two single hyperfragments emitted from a Ξ− nuclear capture at rest was found in a nuclear emulsion. It is interpreted as a Ξ−-12C bound system decaying into either a) Λ4H + Λ9Be, b) Λ 4 H + Λ 9 Be ∗ or c) Λ 4 H ∗ + Λ 9 Be . The binding energy of the Ξ-12C system is obtained as a) 3.70−0.19+0.18 MeV, b) 0.62−0.19+0.18 MeV and c) 2.66−0.19+0.18 MeV, respectively. The system is considered as a Ξ− hypernucleus in the cases a) and c). In case b), this event and another event of the same type (Yokohama event) can both be interpreted as a decay from the Ξ-12C system in 2P state when a shallow Ξ−-nuclear potential is assumed.

Search for Θ+ via π−p→K−X reaction near production threshold

We have searched for

Quasifree p(K-,K+)Xi- reaction in nuclear emulsion

\Theta^{+}

Production of twin λ-hypernuclei from ξ- hyperon capture at rest

via

Measurement of B(Ds+ → μ+νμ)B(Ds+ → φμ+νμ) and determination of the decay constant fDs

\pi^{-}p \to K^{-}X

New techniques for emulsion analysis in a hybrid experiment

reaction using 1.87 and 1.92 GeV/c

Doubly strange nuclei by a hybrid-emulsion experiment E373 at KEK

\pi^{-}

Study of double strangeness nuclei by an emulsion scintillating fiber hybrid method

beam at the K2 beam line of the KEK 12 GeV Proton Synchrotron. In the missing mass spectrum at beam momentum of 1.92 GeV/

Observation of double-hypernuclei and Λ-Λ interaction

c