Search

The main goal of the HyperNIS experiment is the search for the lightest neutron-rich hypernuclei, in particular, $$_{{\Lambda }}^{{\text{6}}}{\text{H}}$$ and the poorly studied $$_{{\Lambda }}^{{\text{6}}}{\text{He}}{\text{,}}$$ and to measure the lifetimes and production cross sections of these hypernuclei. In order to measure the masses of the hypernuclei, it is necessary to determine the momenta of their decay products, including pions. The time-of-flight (TOF) method is planned to be used to measure the pion momenta. Simulation results show that this method provides sufficient accuracy for recovering the masses of the hypernuclei. The structure of the TOF system detectors and the results of the study of their characteristics are presented.

The trigger system of the HyperNIS spectrometer, which was proposed for distinguishing events with the formation and subsequent decay of relativistic hyperfragments, is described. The operation of the system is based on detecting the charges of the hyperfragment and the product nucleus in two-particle π–-meson decay. The events are selected using scintillation and Cherenkov counters. This article presents the results of a methodological work on updating the equipment and software of the experiment, describes the characteristics of trigger detectors, and discusses the specificities of using the trigger system in the planned experiment on the search for the $${}_{{\Lambda }}^{6}{\text{H}}$$ hypernucleus. The expected efficiency and noise immunity of the event selection system are estimated.