Centrality dependence of pi- production and stopping in p - A collisions at 18-GeV/c

Collaboration
Feb, 1999
5 pages
e-Print:
Report number:
  • UCRL-JC-133113
Experiments:

Citations per year

19992004200920142019012345
Abstract:
First results are presented from BNL experiment E910 on pion production and stopping in proton-Be, Cu, and Au collisions at a beam momentum of 18 GeV/c. We characterize the centrality of the collisions using the measured number of "grey" tracks, Ngrey,and a derived quantity, nu, the number of inelastic nucleon-nucleon scatterings suffered by the projectile during the collision. We find that for the three targets the average backward rapidity shift of the leading proton follows a common trend versus nu with the projectile losing, on average, 2 units of rapidity in the first 2-3 scatterings. The average rapidity shift increases more slowly with subsequent scatterings reaching a maximum of 2.5 units. The pi- multiplicity measured within the E910 acceptance saturates with increasing nu in p-Au collisions while the pi- multiplicity in p-Be collisions increases faster with nu than expected from the wounded-nucleon model. Comparisons of our data with the RQMD cascade model suggest that in very central p-Au collisions most of the pions are produced near zero rapidity in the lab.
Note:
  • Submitted to Phys.Rev.Lett.
  • p nucleus: inclusive reaction
  • pi-: hadroproduction
  • beryllium
  • copper
  • gold
  • pi-: multiplicity
  • dependence: impact parameter
  • p: energy loss
  • p: leading particle
  • rapidity