High-energy photons in neutron-proton and proton-nucleus collisions

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.39.1475· OSTI ID:6444661

Nakayama, K

In an effort to better understand the dynamics of nucleon-nucleon bremsstrahlung in producing energetic photons, we have investigated the contribution of each part of the current associated with the different terms in the nuclear Hamiltonian to the neutron-proton bremsstrahlung cross sections. In the range of photon energy investigated here, we find meson-exchange currents to be the dominant source of high-energy photons (..omega..approx. >50 MeV). Although the one-body current contribution is small for such energetic photons, its interference with the two-body current is important and enhances the cross section. At low photon energy the convection current dominates. We find that the bremsstrahlung cross section is very sensitive to the /sup 3/(SD)/sub 1/ states and offers a potential means of investigating short-range correlation effects. Off-energy-shell effects are estimated to have only a small influence on the neutron-proton bremsstrahlung inclusive cross section. In connection with the neutron-proton bremsstrahlung process, the nucleon-nucleon collisional mechanism in producing high-energy photons in proton-induced reactions has been also investigated within the nuclear matter approximation. Nuclear medium effects in intermediate states are shown to have a minor influence on the photon cross section; therefore, the use of a free nucleon-nucleon T matrix instead of a G matrix seems to be well justified. However, the results are found to be very sensitive to medium effects in the initial and final states.

• Research Organization: Department of Physics and Astronomy, University of Georgia, Athens, Georgia 30602
• OSTI ID: 6444661
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 39:4; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
BARYON-BARYON INTERACTIONS
BOSON-EXCHANGE MODELS
BOUNDARY CONDITIONS
BREMSSTRAHLUNG
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FUNCTIONS
G MATRIX
GAUGE INVARIANCE
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
HAMILTONIANS
INCLUSIVE INTERACTIONS
INTERACTIONS
INVARIANCE PRINCIPLES
MASSLESS PARTICLES
MATHEMATICAL MODELS
MATHEMATICAL OPERATORS
MATRICES
MATTER
NUCLEAR MATTER
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUCLEON-NUCLEON INTERACTIONS
PARTICLE INTERACTIONS
PARTICLE MODELS
PERIPHERAL MODELS
PHOTONS
PROTON REACTIONS
PROTON-NEUTRON INTERACTIONS
PROTON-NUCLEON INTERACTIONS
QUANTUM OPERATORS
RADIATIONS
S MATRIX
WAVE FUNCTIONS