Decay Pion Spectroscopy of Double-Λ Hypernuclei at J-PARC

Double-Λ hypernuclei provide invaluable information on Λ–Λ interaction, as a scattering experiment with a hyperon target is impossible. For more than half a century, double-Λ hypernuclei have been searched for by using nuclear emulsion. We will propose a novel counter experiment (J-PARC P75 experiment), aiming at investigating a light double-Λ hypernucleus, \(_{\Lambda \Lambda }^{\ \ \ 5}\text{H}\). The ΛΛ binding energy will be determined by decay pion spectroscopy. The experimental method of production and identification of \(_{\Lambda \Lambda }^{\ \ \ 5}\text{H}\) is discussed.