The recently measured energy-momentum spectral functions P ( k, E ) by the CLAS collaboration in triple-coincidence A ( e, e ′ Np ) measurements allow for improved studies of subthreshold particle production in proton heavy-ion collisions. The observed short range correlations (SRC) enhance the available center of mass energy of individual nucleon-nucleon collisions and allow therefore for sub-threshold particle production in proton-nucleus collisions. Calculations demonstrate that SRC enhance the probability for particle production at nominal sub-threshold energies up to a factor of × 10 3 as compared to a simple Fermi gas model. We benchmark the idea by calculating the Ξ − multiplicity in nominal sub-threshold p+Nb collisions using both a Fermi and a SRC nucleus, which both compare well with the data measured by the HADES collaboration. The calculations show, however, that deep below threshold a substantial increase of the Ξ − yield is expected. These findings are of prime relevance for upcoming experiments at the FAIR facility, especially for the study of charmed hadrons.
The influence of nuclear short range correlations on sub-threshold particle production in proton-nucleus collisions
Tom Reichert·Jörg Aichelin

