Electron Coulomb effects in quasielastic ( e , e prime p ) reactions

Journal Article · Sun Mar 01 00:00:00 EST 1992 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.45.1311· OSTI ID:7277292

Jin, Y; Onley, D S; Wright, L E ^[1]

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1. Physics Department, Ohio University, Athens, Ohio 45701 (United States)

We describe a calculation for the electron Coulomb distortion effects in ({ital e},{ital e}{prime}{ital p}) in the quasielastic region from medium and heavy nuclei. The bound nucleons are described by single-particle Dirac wave functions in the presence of scalar and vector potentials which are parametrized fits to relativistic Hartree potentials, while the wave function of the knocked-out nucleon is a solution to the Dirac equation with the relativistic optical potential. The electron wave functions are solutions to the Dirac equation in the presence of the Coulomb potential of the nucleus and the interaction with the selected nucleon is treated to first order. We examine the {sup 40}Ca({ital e},{ital e}{prime}{ital p}) reaction in both parallel and {omega}-{ital q} constant kinematics. We find that electron Coulomb distortion has a smaller effect in {omega}-{ital q} constant kinematics than in parallel kinematics. The principal effect in parallel kinematics is to shift the maximum and minimum of the reduced cross section which is consistent with the experimental data. Occupation numbers of about 70% to 80% are needed to normalize the distorted-wave Born approximation calculation to the {sup 40}Ca({ital e},{ital e}{prime}{ital p}) experimental data. We also calculate the reduced cross section for the 3{ital s}{sub 1/2} state in {sup 208}Pb and compare our results to experimental data and previous calculations. We find no significant difference in using relativistic, as compared with nonrelativistic, nuclear wave functions. We do find significant corrections to earlier methods of treating Coulomb distortion which, in turn, affect the occupation number extracted from experiment. We find an occupation number for this state of 71.4%.

• DOE Contract Number: FG02-87ER40370
• OSTI ID: 7277292
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Vol. 45:3; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CALCIUM 40 REACTIONS
ELECTRON REACTIONS
QUASI-ELASTIC SCATTERING
COULOMB CORRECTION
DIFFERENTIAL CROSS SECTIONS
DIRAC EQUATION
DWBA
KNOCK-OUT REACTIONS
OPE POTENTIAL
OPTICAL MODELS
PROTONS
RELATIVISTIC RANGE
BARYONS
BORN APPROXIMATION
CHARGED-PARTICLE REACTIONS
CORRECTIONS
CROSS SECTIONS
DIFFERENTIAL EQUATIONS
DIRECT REACTIONS
ELEMENTARY PARTICLES
ENERGY RANGE
EQUATIONS
FERMIONS
HADRONS
HEAVY ION REACTIONS
LEPTON REACTIONS
NUCLEAR REACTIONS
NUCLEONS
PARTIAL DIFFERENTIAL EQUATIONS
POTENTIALS
QUASI-FREE REACTIONS
SCATTERING
WAVE EQUATIONS
663420* - Lepton-Induced Reactions & Scattering- (1992-)
663540 - Nuclear Mass Ranges- A=39-58- (1992-)