arXiv subjects
Publications and source records attributed to D. Di Santo.
The production of neutron rich $Λ$-hypernuclei via the ($K^-_stop$,$π^+$) reaction has been studied using data collected with the FINUDA spectrometer at the DA$Φ$NE $ϕ$-factory (LNF). The analysis of the inclusive $π^+$ momentum spectra is presented and an upper limit for the production of $^6_Λ$H and $^7_Λ$H from $^6$Li and $^7$Li, is assessed for the first time.
Momenta spectra of protons emitted following the capture of $K^-$ in $^6$Li and $^{12}$C have been measured with 1% resolution. The $^{12}$C spectrum is smooth whereas for $^6$Li a well defined peak appears at about 500 MeV/$c$. The first observation of a structure in this region was identified as a strange tribaryon or, possibly, a $\bar K$-nuclear state. The peak is correlated with a $π^-$ coming from $Σ^-$ decay in flight, selected by setting momenta larger than 275 MeV/$c$. The $Σ^-$ could be produced, together with a 500 MeV/$c$ proton, by the capture of a $K^-$ in a deuteron-cluster substructure of the $^6$Li nucleus. The capture rate for such a reaction is $(1.62\pm 0.23_{stat} ^{+0.71}_{-0.44}(sys))%/K^-_{stop}$, in agreement with the existing observations on $^4$He targets and with the hypothesis that the $^6$Li nucleus can be interpreted as a $(d+α)$ cluster.
Experimental information has been derived from the neutron-proton correlation function in order to deduce the time sequence of neutrons and protons emitted at 45 degrees in the E/A = 45 MeV 58Ni + 27Al reaction.