Relativistic distorted-wave impulse approximation analysis of {sup 12}C(e,e{sup '}p) for Q{sup 2}<2 (GeV/c){sup 2}

Journal Article · Wed Jun 01 00:00:00 EDT 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.71.064610· OSTI ID:20698766

Kelly, James J ^[1]

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1. Department of Physics, University of Maryland, College Park, Maryland 20742 (United States)

We analyze data for {sup 12}C(e,e{sup '}p) with Q{sup 2}<2 (GeV/c){sup 2} using the relativistic distorted-wave impulse approximation (RDWIA) based upon Dirac-Hartree wave functions. The 1p normalization extracted from data for Q{sup 2}>0.6 (GeV/c){sup 2} is approximately 0.87, independent of Q{sup 2}, which is consistent with the predicted depletion of the 1p{sub 3/2} orbital by short-range correlations. The total 1p and 1s strength for E{sub m}<80 MeV approaches 100% of IPSM (independent particle shell model), consistent with a continuum contribution for 30<E{sub m}<80 MeV of about 12% of IPSM. Similarly, a scale factor of 1.12 brings RDWIA calculations into good agreement with {sup 12}C(e,e{sup '}p) data for transparency. We also analyzed low Q{sup 2} data from which a recent nonrelativistic RDWIA analysis suggested that spectroscopic factors might depend strongly upon the resolution of the probe. We find that the momentum distributions for their empirical Woods-Saxon wave functions fit to low Q{sup 2} data for parallel kinematics are too narrow to reproduce data for quasiperpendicular kinematics, especially for larger Q{sup 2}, and are partly responsible for reducing fitted normalization factors. Although the RDWIA normalization factors for Q{sup 2}<0.2 (GeV/c){sup 2} are also smaller than obtained for Q{sup 2}>0.6 (GeV/c){sup 2}, the effect is smaller, and we argue that it should be attributed to the effective single-nucleon current operator instead of to spectroscopic factors, which are probe-independent properties of nuclear structure. However, remediation of the failure of RDWIA calculations to reproduce low Q{sup 2} data for parallel kinematics will require a more sophisticated modification of the current method than a simple multiplicative factor.

• OSTI ID: 20698766
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 71, Issue 6; Other Information: DOI: 10.1103/PhysRevC.71.064610; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CARBON 12
CORRELATIONS
DISTORTED WAVE THEORY
DISTRIBUTION
DWBA
ELECTRON REACTIONS
ELECTRONS
FOUR MOMENTUM TRANSFER
GEV RANGE
IMPULSE APPROXIMATION
MEV RANGE
NUCLEAR STRUCTURE
OPACITY
OPTICAL MODELS
RELATIVISTIC RANGE
SHELL MODELS
SPECTROSCOPIC FACTORS
WAVE FUNCTIONS
WOODS-SAXON POTENTIAL