Abnormally Large Momentum Loss in Charge Pickup by 900-MeV/Nucleon Au Nuclei

Abstract
Using a thin stack of glass detectors to measure Zβ of forward-projected fast fragments from interactions of 900-MeV/nucleon Au197 nuclei, we measure a cross section of 35 ± 8 mb for charge pickup (ΔZ=+1) from Au to Hg, and we infer a mean velocity downshift δβ0.004 and a mean momentum downshift δp6 GeV/c for Au to Hg, 2 orders of magnitude larger than observed for charge pickup by light nuclei. Implications of this result are discussed.