Effect of multiple scattering on the measurement of nuclear transparency.

Abstract

An expression for the measured nuclear transparency in quasielastic high energy ({ital p},2{ital p}) reactions is derived in a semiclassical approach which includes the multiple elastic scattering (MS) of the incoming and outgoing protons. It is shown that if one ignores MS in the analysis of the experimental data, an {ital artificial} energy dependence of the transparency will be observed. The transparency increases with incident momentum, but its absolute value is {ital less} than that predicted by the conventional semiclassical (Glauber) picture. We demonstrate that it is sufficient to apply a simple selection of data, based on an energy resolution of approximately 100 MeV, to avoid the artifact of the neglected MS. We also show that the MS cannot explain the absolute {ital increase} of nuclear transparency observed in ({ital p},2{ital p}) large angle data, nor can it account for its incident momentum dependence.