WASA-FRS HypHI experiment at GSI for studying light hypernuclei

Abstract

From January till March 2022, the WASA-FRS HypHI experiment performed a precise measurement of the hypertriton and the 4ΛH hypernucleus lifetime at GSI. The data collected should also confirm whether or not the nnΛ bound state can exist. The experiment were carried out with the WASA central detector with a complex of additional dedicated detectors mounted together at the mid-focal plane of the high-momentum-resolution forward spectrometer, the so-called fragment separator FRS. Hypernuclei of interest were produced by induced reactions of 6Li projectiles at 1.96 A GeV on a diamond target with a thickness of 9.87 g/cm2. Negatively charged π mesons from two-body decays of the hypernuclei of interest were measured by theWASA and the other detectors, and the residual nuclei after the π− decay were measured by the FRS with a momentum resolving power of 104.