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On the Space-Time Difference of Proton and Composite Particle Emission in Central Heavy-Ion Reactions at 400 AMeV

R. Kotte·H. W. Barz·C. Plettner·W. Neubert·D. Wohlfarth·the FOPI collaboration
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Abstract

Small-angle correlations of pairs of nonidentical light charged particles produced in central collisions of heavy ions in the A=100 mass region at a beam energy of 400 AMeV are investigated with the FOPI detector system at GSI Darmstadt. The difference of longitudinal correlation functions with the relative velocity parallel and anti-parallel to the center-of-mass velocity of the pair in the central source frame is studied. This method allows extracting the apparent space-time differences of the emission of the charged particles. Comparing the correlations with results of a final-state interaction model delivers quantitative estimates of these asymmetries. Time delays as short as 1 fm/c or - alternatively - source radius differences of a few tenth fm are resolved. The strong collective expansion of the participant zone introduces not only an apparent reduction of the source radius but also a modification of the emission times. After correcting for both effects a complete sequence of space-time emission points of p, d, t, 3He, alpha particles is presented for the first time.

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R. Kotte, H. W. Barz, C. Plettner, W. Neubert, D. Wohlfarth, the FOPI collaboration. 1999-08-17. On the Space-Time Difference of Proton and Composite Particle Emission in Central Heavy-Ion Reactions at 400 AMeV. https://arxiv.org/abs/nucl-ex/9904007

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