Exclusive studies of angular distributions in GeV hadron-induced reactions with Au-197 Academic Article uri icon


  • Exclusive studies of angular distributions for intermediate-mass fragments (IMFs) produced in GeV hadron-induced reactions have been performed with the Indiana Silicon Sphere (ISiS) 4 detector array. Special emphasis has been given to understanding the origin of sideways peaking, which becomes prominent in the angular distributions for beam momenta above about [Formula Presented] Both the magnitude of the effect and the peak angle increase as a function of fragment multiplicity and charge. When gated on IMF kinetic energy, the angular distributions evolve from forward-peaked to near isotropy as the fragment kinetic energy decreases. Fragment-fragment angular-correlation analyses show no obvious evidence for a dynamic mechanism that might signal shock wave effects or the breakup of exotic geometric shapes such as bubbles or toroids. Moving-source and intranuclear cascade simulations suggest that the observed sideways peaking is of kinematic origin, arising from significant transverse momentum imparted to the heavy recoil nucleus during the fast cascade stage of the collision. A two-step cascade and statistical multifragmentation calculation is consistent with this assumption. 1999 The American Physical Society.

published proceedings


author list (cited authors)

  • Hsi, W. C., Kwiatkowski, K., Wang, G., Bracken, D. S., Cornell, E., Ginger, D. S., ... Friedman, W. A.

citation count

  • 15

complete list of authors

  • Hsi, WC||Kwiatkowski, K||Wang, G||Bracken, DS||Cornell, E||Ginger, DS||Viola, VE||Korteling, RG||Morley, KB||Huang, R||Lynch, WG||Tsang, MB||Xi, H||Gimeno-Nogues, F||Ramakrishnan, E||Rowland, D||Yennello, SJ||Breuer, H||Gushue, S||Remsberg, LP||Botvina, A||Friedman, WA

publication date

  • September 1999