E2 CONTRIBUTION TO THE B-8-]P+BE-7 COULOMB DISSOCIATION CROSS-SECTION - COMMENT

The E2 cross section calculated by Langanke and Shoppa for the RIKEN experiment on the Coulomb dissociation of B-8 uses E2 nuclear matrix element from one specific model. Other nuclear models predict a considerably smaller E2 cross section (by approximately a factor of 3 to 4), and Langanke and Shoppa appear to assume the most optimistic scenario, predicting a large E2 cross section. We also note that Barker has already criticized the nuclear model used by Langanke and Shoppa. A model independent chi-square analysis of the RIKEN data suggest the best fit for the current RIKEN data is obtained with El amplitudes only. The upper limit (90% confidence) on the E2 component derived from our chi-square analysis is considerably smaller than that used by Langanke and Shoppa. The model dependent analysis of Langanke and Shoppa should not be considered as a correction to the RIKEN result, as claimed, and their quoted S-17(0) is not substantiated.