Study Of Short-Range Correlations With 6-9 GeV/c Protons

We studied the 12C(p,2p+n) reaction at beam momenta of 5.9, 8.0 and 9.0 GeV/c. For quasielastic (p,2p) events we reconstructed pf, the momentum of the knocked-out proton before the reaction;, pf was then compared (event-by-event) with pn, the measured, coincident neutron momentum. For |pn|>kF = 0.220 GeV/c(the Fermi momentum) a strong back-to-back directional correlation between pf and pn was observed, indicative of short-range n-p correlations. From these data we concluded that for nuclear protons with momenta >0.275 GeV/c, 92±18% have correlated neutron partners. This result was recently corroborated by an experiment with 4.6 GeV electrons.