RT Journal Article
T1 Forward doubly-virtual Compton scattering off the nucleon in chiral perturbation theory. II. Spin polarizabilities and moments of polarized structure functions
A1 Alarcón, Jose Manuel
A1 Hagelstein, Franziska
A1 Lensky, Vadim
A1 Pascalutsa, Vladimir
AB We examine the polarized doubly-virtual Compton scattering (VVCS) off the nucleon using chiral perturbation theory ( χ PT ). The polarized VVCS contains a wealth of information on the spin structure of the nucleon which is relevant to the calculation of the two-photon-exchange effects in atomic spectroscopy and electron scattering. We report on a complete next-to-leading-order calculation of the polarized VVCS amplitudes S 1 ( ν , Q 2 ) and S 2 ( ν , Q 2 ) , and the corresponding polarized spin structure functions g 1 ( x , Q 2 ) and g 2 ( x , Q 2 ) . Our results for the moments of polarized structure functions, partially related to different spin polarizabilities, are compared to other theoretical predictions and “data-driven” evaluations, as well as to the recent Jefferson Lab measurements. By expanding the results in powers of the inverse nucleon mass, we reproduce the known “heavy-baryon” expressions. This serves as a check of our calculation, as well as demonstrates the differences between the manifestly Lorentz-invariant baryon χ PT and heavy-baryon frameworks.
PB APS Physics
SN 2470-0010
YR 2020
FD 2020-12-17
LK https://hdl.handle.net/20.500.14352/7267
UL https://hdl.handle.net/20.500.14352/7267
LA eng
NO Ministerio de Educación, Cultura y Deporte (MECD)
NO Deutsche Forschungsgemeinschaft (DFG)
DS Docta Complutense
RD 10 abr 2025