Gauge invariance and Compton scattering from relativistic composite systems

Technical Report · Wed Sep 01 04:00:00 EDT 1993

DOI:https://doi.org/10.2172/10102544· OSTI ID:10102544

Ito, H ^[1]; Gross, F ^[2]

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1. George Washington Univ., Washington, DC (United States). Center for Nuclear Studies
2. Continuous Electron Beam Accelerator Facility, Newport News, VA (United States)

Using the Ward-Takahashi (W-T) identity and the Bethe-Salpeter (B-S) wave equation, we investigate the dynamical requirements imposed by electromagnetic gauge invariance on Compton scattering from relativistic composite system. The importance of off-shell rescattering in intermediate states, which is equivalent to final state interactions in inclusive processes, is clarified in the context of current conservation. It is shown that, if the nuclear force is nonlocal, there will be both two-photon interaction currents and rescattering contributions to terms involving one-photon interaction currents. We derive the two-body W-T identity for the two-photon interaction currents, and obtain explicit forms for the interaction current operators for three illustrative models of nuclear forces: (a) two-pion exchange forces with baryon resonances, (b) covariant separable forces, and (c) charged one-pion exchange.

• Research Organization: Southeastern Universities Research Association, Inc., Newport News, VA (United States). Continuous Electron Beam Accelerator Facility
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 10102544
• Report Number(s): DOE/ER/40150--239; WM--93-103; CEBAF-TH--93-10; ON: DE93040858
• Country of Publication: United States
• Language: English

Related Subjects

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662130
662330
662390
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CEBAF ACCELERATOR
COMPTON EFFECT
ELECTROMAGNETIC PROCESSES AND PROPERTIES
GAUGE INVARIANCE
PHOTON AND CHARGED-LEPTON INTERACTIONS WITH HADRONS
PHOTON-PHOTON INTERACTIONS
RELATIVISTIC RANGE
S-MATRIX THEORY
RELATIVISTIC SCATTERING THEORY
SYMMETRY
CONSERVATION LAWS
CURRENTS AND THEIR PROPERTIES
WARD IDENTITY