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

Journal Article · Wed Jul 01 04:00:00 EDT 1987 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.36.193· OSTI ID:5977993

Webb, M L; Crawford, H J; Engelage, J; Baumgartner, M E; Greiner, D E; Lindstrom, P J; Olson, D L; Wada, R

We 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 as follows: (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. 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 3. The low momentum transfer 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 to 190 +- 11 MeV/c from the longitudinal momentum distribution.

• Research Organization: University of California at Davis, Davis, California 95616
• OSTI ID: 5977993
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 36:1; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651320* -- Nuclear Properties & Reactions
A=6-19
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON-BARYON INTERACTIONS
BARYONS
BORON 11
BORON ISOTOPES
BOSONS
CARBON
CARBON 12 REACTIONS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DIRECT REACTIONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
EXPERIMENTAL DATA
FERMIONS
FRAGMENTATION
GEV RANGE
GEV RANGE 10-100
HADRON-HADRON INTERACTIONS
HADRONS
HEAVY ION REACTIONS
HYDROGEN 1 TARGET
INELASTIC SCATTERING
INFORMATION
INTERACTIONS
ISOTOPES
LIGHT NUCLEI
MATHEMATICAL SPACE
MEASURING INSTRUMENTS
MESONS
MOMENTUM TRANSFER
NONMETALS
NUCLEAR REACTIONS
NUCLEI
NUCLEON-NUCLEON INTERACTIONS
NUCLEONS
NUMERICAL DATA
ODD-EVEN NUCLEI
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PHASE SPACE
PIONS
PROTONS
PSEUDOSCALAR MESONS
QUASI-ELASTIC SCATTERING
QUASI-FREE REACTIONS
RADIATION DETECTORS
SCATTERING
SCINTILLATION COUNTERS
SPACE
STABLE ISOTOPES
TARGETS
TIME-OF-FLIGHT METHOD