Coulomb dissociation in relativistic heavy ion reactions

Targets of 12C, 59Co, 89Y, 197Au and 238U were bombarded by 2.1 GeV/A 1H, 12C and 20Ne projectiles using the SuperHILAC and BEVATRON facilities at Lawrence Berkeley Laboratory (LBL). The beam flux was calculated by monitoring the decay of 11C produced from the 12C(projectile,projectile n)11C reaction. Residual gamma-ray activity from the Co, Y, Au and U targets was collected in order to trace the decay of several reaction products. The experiment focused on the calculation of cross sections for the formation of products with one neutron removed from the various target nuclei. Corrections to the saturation activity of each product were made for detector efficiency, gamma-ray absorption in the target, gamma-ray branching, beam geometry and secondary reactions. These date are shown to be inconsistent with a geometrical form given by sigma varies as (A/sub p/sup 1/3/ + A/sub t/sup 1/3/ - b) where b is a universal constant. In fact the data indicates the b = A/sub t/sup 1/3/. Instead the data can be fit quite well by a simple empirical relation, sigma/sub emp/ = 12.0 mb A/sub p/sup 1/3/ A/sub t/sup 1/3/. It is demonstrated that an empirical fit which varies as A/sub t/sup 1/3/ is also consistent with projectile fragmentation data measured by a group at LBL. In addition these data are compared to a theoretical prediction which is the sum of a renormalized Glauber term and a term which represents the contribution due to Coulomb or electromagnetic dissociation (ED). The theoretical predictions are quite low for the 12C projectile data and high for the 20Ne projectile data. The systematic trends from the comparison seem to indicate that theoretical prediction for the ED contribution is rising too fast as a function of projectile for a given target