Virtual Compton scattering off the nucleon at low energies

Journal Article · Thu Aug 01 04:00:00 EDT 1996 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.54.904· OSTI ID:288196

Scherer, S ^[1]; Korchin, A Y ^[2]; Koch, J H ^[3]

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1. Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany)
2. National Scientific Center Kharkov Institute of Physics and Technology, 310108 Kharkov (Ukraine)
3. National Institute for Nuclear Physics and High-Energy Physics, 1009 DB Amsterdam (The Netherlands)

We investigate the low-energy behavior of the four-point Green{close_quote}s function {Gamma}{sup {mu}{nu}} describing virtual Compton scattering off the nucleon. Using Lorentz invariance, gauge invariance, and crossing symmetry, we derive the leading terms of an expansion of the operator in the four-momenta {ital q} and {ital q}{sup {prime}} of the initial and final photon, respectively. The model-independent result is expressed in terms of the electromagnetic form factors of the free nucleon, i.e., on-shell information which one obtains from electron-nucleon scattering experiments. Model-dependent terms appear in the operator at {ital O}({ital q}{sub {alpha}}{ital q}{sub {beta}}{sup {prime}}), whereas the orders {ital O}({ital q}{sub {alpha}}{ital q}{sub {beta}}) and {ital O}({ital q}{sub {alpha}}{sup {prime}}{ital q}{sub {beta}}{sup {prime}}) are contained in the low-energy theorem for {Gamma}{sup {mu}{nu}}, i.e., no new parameters appear. We discuss the leading terms of the matrix element and comment on the use of on-shell equivalent electromagnetic vertices in the calculation of {open_quote}{open_quote}Born terms{close_quote}{close_quote} for virtual Compton scattering. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 288196
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 2 Vol. 54; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
COMPTON EFFECT
CROSSING SYMMETRY
ELECTROMAGNETIC FORM FACTORS
ELECTRON-NUCLEON INTERACTIONS
GAUGE INVARIANCE
GREEN FUNCTION
LORENTZ INVARIANCE
LOW-ENERGY THEOREM
MATRIX ELEMENTS
NUCLEONS
PHOTON-NUCLEON INTERACTIONS