Related Experiment Video
Updated: Jul 7, 2026

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Two-photon-exchange and gammaZ-exchange corrections to parity-violating elastic electron-proton scattering
Hai Qing Zhou1, Chung Wen Kao, Shin Nan Yang
1Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
Abstract:
Leading electroweak corrections play an important role in precision measurements of the strange form factors. We calculate the two-photon-exchange (TPE) and gammaZ-exchange corrections to the parity-violating asymmetry of the elastic electron-proton scattering in a simple hadronic model including the finite size of the proton. We find both can reach a few percent and are comparable in size with the current experimental measurements of strange-quark effects in the proton neutral weak current. The effect of gammaZ exchange is in general larger than that of TPE, especially at low momentum transfer Q2=1 GeV2. Their combined effects on the values of G(E)s + beta G(M)s [corrected] extracted in recent experiments can be as large as -40% in certain kinematics.
Related Concept Videos
π Electron Effects on Chemical Shift: Overview
Nuclear Overhauser Enhancement (NOE)
The Pauli Exclusion Principle
Types of Radioactivity
Alpha (α) decay is the emission of an α particle from the nucleus. For example, polonium-210 undergoes α decay:
Thomson's e/m Experiment
A particle with charge q, speed v, and mass m enters an area from the top, where the magnetic and electric fields are perpendicular both to the particle's motion and to one another. The magnetic...
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

