Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Probing the direct step of relativistic heavy-ion fragmentation (/sup 12/C, /sup 11/B + p) at 2. 1 GeV/nucleon with C and CH/sub 2/ targets

Thesis/Dissertation ·
OSTI ID:5919220
The authors have measured the momentum distributions and the excitation energy of the p, /sup 11/B pair in the (/sup 12/C, /sup 11/B + p) reaction at 2.1 GeV/nucleon with C and CH/sub 2/ targets. The cross section separates into three regions: (1) nucleon-nucleon quasi-elastic scattering, (2) nucleon-nucleon inelastic scattering, and (3) a low excitation energy and momentum transfer peak. The cross sections, by region, are: (1) 8.8 +/- 2.5 mb, (2) 10.1 +/- 2.2 mb, and (3) 0.81 +/- 0.45 mb for H(/sup 12/C, /sup 11/B + p)X, and (1) 11.1 +/- 2.4 mb, (2) 24.1 +/- 3.7 mb, and (3) 4.50 +/- 0.67 mb for C(/sup 12/C, /sup 11/B + p)X. All errors are standard deviations. The shapes of the first two regions can be fit with a nucleon-nucleon cascade model including ..pi.. production. However, the cascade model prediction for the quasi-elastic component is too large by a factor of three. The peak is consistent with two mechanisms, (1) an excitation and decay via proton emission of the carbon projectile, and (2) a projectile proton scattering diffractively off the C target. Finally, the Fermi momentum determined from the transverse momentum distribution is 160 +/- 11 MeV/c compared with 190 +/- 11 MeV/c from the longitudinal momentum distribution.
Research Organization:
California Univ., Davis (USA)
OSTI ID:
5919220
Country of Publication:
United States
Language:
English