Signals for a transition from surface to bulk emission in thermal multifragmentation.
/ Authors
L. Beaulieu, T. Lefort, K. Kwiatkowski, R. T. D. Souza, W. Hsi, L. Pieńkowski, B. Back, D. Bracken, H. Breuer, E. Cornell
and 15 more authors
F. Gimeno-Nogues, D. Ginger, S. Gushue, R. Korteling, R. Laforest, E. Martin, K. Morley, E. Ramakrishnan, L. Remsberg, D. Rowland, A. Ruangma, V. Viola, G. Wang, E. Winchester, S. Yennello
/ Abstract
Excitation-energy-gated two-fragment correlation functions have been studied between E(*)/A = (2-9)A MeV for equilibriumlike sources formed in 8-10 GeV/c pi(-) and p+197Au reactions. Comparison with an N-body Coulomb-trajectory code shows an order of magnitude decrease in the fragment emission time in the interval E(*)/A = (2-5)A MeV, followed by a nearly constant breakup time at higher excitation energy. The decrease in emission time is strongly correlated with the onset of multifragmentation and thermally induced radial expansion, consistent with a transition from surface-dominated to bulk emission expected for spinodal decomposition.
Journal: Physical review letters