The nucleon spin-averaged forward virtual Compton tensor determines important physical quantities such as electromagnetically induced mass differences of nucleons and two-photon exchange contributions in hydrogen spectroscopy. It depends on two kinematic variables: ν, the virtual photon energy in the proton rest frame, and Q2, the photon's invariant four-momentum squared. Using the operator product expansion, we calculate the tensor's large-Q2 behavior for ν=0, including for the first time the full spin-2 contribution and correcting a previous result in the literature for the spin-0 contribution. Implications for the proton radius puzzle are discussed.
|Journal||Physical Review D|
|State||Published - May 1 2017|
Bibliographical notePublisher Copyright:
© 2017 American Physical Society.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)