What can we learn about baryon-baryon interaction from hypernuclei Λ6H and Λ8H?

At the LHE JINR, an original approach to hypernuclear experiments was elaborated to produce relativistic hypernuclei. The production cross sections and lifetimes, τ, of Λ3H and Λ4H were measured successfully. The results of recent experiments on 5H and 7H nuclei suggest that the hypernucleus Λ6H might be stable and that this may be the case even for Λ8H. The unique quality of the spectrometer SPHERE may be used to identify unambiguously the isotopes of hyperhydrogen—through their pionic decay ΛAH → π− + AHe—including the new hypernuclei Λ6H and Λ8H with extreme values of N/Z of 4 and 6, respectively. The confirmation of the very existence of these neutron-rich hypernuclei would be a strong motivation to search for their spectra in strangeness and double-charge-exchange reactions (Kstop−, π+) at FINUDA or (π−, K+) at J-PARC. It is very probable that, similarly as in Λ4H, there is a low-lying state 1+ also in Λ6H and Λ8H. If their electromagnetic width (M1) is small enough, we could see two different values of τ for Λ6H and/or Λ8H. We investigate the spacings of the 1+ and 0+ states of Λ4H, Λ6H, and Λ8H. The understanding of the structure of isospin asymmetric systems plays a key role in the description of systems as diverse as neutron-rich nuclei and neutron matter.