Electron-deuteron scattering in the equal-time formalism: beyond the impulse approximation

Journal Article · Mon Nov 01 04:00:00 EST 2004

OSTI ID:836168

Phillips, D R; Wallace, Stephen; Devine, N K

Using a three-dimensional formalism that includes relativistic kinematics, the effects of negative-energy states, approximate boosts of the two-body system, and current conservation, we calculate the electromagnetic form factors of the deuteron up to Q{sup 2} of 4 GeV{sup 2}. This is done using a dynamical boost for two-body systems with spin. We first compute form factors in impulse approximation, but then also add an isoscalar meson-exchange current of pion range that involves the gamma-pi contact operator associated with pseudovector pi-N coupling. We also consider effects of the rho-pi-gamma meson-exchange current. The experimentally measured quantities A, B, and t20 are calculated over the kinematic range probed in recent Jefferson Laboratory experiments. The rho-pi-gamma meson-exchange current provides significant strength in A at large Q{sup 2} and the gamma-pi contact-term exchange current shifts t20, providing good agreement with the JLab data. Relativistic effects and the gamma-pi meson-exchange current do not provide an explanation of the B observable, but the rho-pi-gamma current could help to provide agreement if a nonstandard value is used for the tensor rho-N coupling that enters this contribution.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (US)
• Sponsoring Organization: USDOE Office of Energy Research (ER) (US)
• DOE Contract Number: AC05-84ER40150
• OSTI ID: 836168
• Report Number(s): JLAB-THY-04-49; DOE/ER/40150-3064; nucl-th/0411092
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BOSON-EXCHANGE MODELS
CEBAF ACCELERATOR
DEUTERONS
ELECTROMAGNETIC FORM FACTORS
FORM FACTORS
IMPULSE APPROXIMATION
PIONS
SCATTERING
SPIN