Contribution of Two-Boson-Exchange with $\Delta (1232)$ Excitation to Parity-Violating Elastic Electron-Proton Scattering

Abstract

We study the leading electroweak corrections in the precision measurement of the strange form factors. Specifically, we calculate the two-boson-exchange (TBE), two-photon-exchange (TPE) plus $\gamma Z$-exchange ($\gamma Z$E), corrections with $\Delta (1232)$ excitation to the parity-violating asymmetry of the elastic electron-proton scattering. The interplay between nucleon and $\Delta$ contributions is found to depend strongly on the kinematics, as ${\delta }_{\Delta }$ begins as negligible at backward angles but becomes very large and negative and dominant at forward angles, while ${\delta }_N$ always stays positive and decreases monotonically with increasing $\epsilon$. The total TBE corrections to the extracted values of $G_E^s+\beta G_M^s$ in recent experiments of HAPPEX and G0 are, depending on kinematics, found to be large and range between 13% to -75% but small in the case of A4 experiments.

5 pages, the result is corrected

References in corpus (6)

• Unitary Isobar Model - MAID2007
• Electromagnetic excitation of the Delta(1232)-resonance
• Precision Measurements of the Nucleon Strange Form Factors at Q^2 ~0.1 GeV^2
• Dispersion $\gamma Z$-box correction to the weak charge of the proton
• The Two-Photon-Exchange and γZ-Exchange Corrections to parity-Violating Elastic Electron-Proton Scattering
• Effect of two-boson exchange on parity-violating e-p scattering

Cited by in corpus (10)

• Review of two-photon exchange in electron scattering
• Two-photon exchange in elastic electron-proton scattering
• Model-dependence of the $\gamma Z$ dispersion correction to the parity-violating asymmetry in elastic $ep$ scattering
• A dispersive approach to two-photon exchange in elastic electron-proton scattering
• $\Delta (1232)$ Resonance Contribution to Two-Photon Exchange in Electron-Proton Scattering Revisited
• On the two-boson exchange corrections to parity-violating elastic electron-proton scattering
• The strangeness form factors of the proton within nonrelativistic constituent quark model revisited
• Two-Boson Exchange Physics: A Brief Review
• $\Delta$ contribution in $e^{+}+e^{-}\to p+\bar{p}$ at small $s$
• Proton strangeness form factors in (4,1) clustering configurations