Longitudinal momentum fraction XL for two high Pt protons in pp→ppX reaction

We present an analysis of new data from Experiment E850 at BNL. We have characterized the inclusive cross section near the endpoint for pp exclusive scattering in Hydrogen and in Carbon with incident beam energy of 6 GeV. We select events with a pair of back-to-back hadrons at large transverse momentum. These cross sections are parameterized with a form dσ/dXL∼(1−XL)p, where XL is the ratio of the longitudinal momentum of the observed pair to the total incident beam momentum. Small value of p may suggest that the number of partons participating in the reaction is large and reaction has a strong dependence on the center-of-mass energy. We also discuss nuclear effects observed in our kinematic region.