Nuclear Transparency in Large Momentum Transfer Quasielastic Scattering

We measured simultaneously pp elastic and quasielastic (p,thinsp2p) scattering in hydrogen, deuterium, and carbon for momentum transfers of 4.8 to 6.2 (GeV/c){sup 2} at incoming momenta of 5.9 and 7.5 GeV/c and center-of-mass scattering angles in the range {theta}{sub c.m.}=83.7{degree} {endash}90{degree} . The nuclear transparency is defined as the ratio of the quasielastic cross section to the free pp cross section. At incoming momentum of 5.9 GeV/c , the transparency of carbon decreases by a factor of 2 from {theta}{sub c.m.}{approx_equal}85{degree} to {theta}{sub c.m.}{approx_equal}89{degree} . At the largest angle the transparency of carbon increases from 5.9 to 7.5 GeV/c by more than 50{percent}. The transparency in deuterium does not depend on incoming momentum nor on {theta}{sub c.m.} . {copyright} {ital 1998} {ital The American Physical Society }