6533b827fe1ef96bd128670a
RESEARCH PRODUCT
Generalized polarizabilities of the nucleon in baryon chiral perturbation theory
Vladimir PascalutsaVadim LenskyVadim LenskyMarc Vanderhaeghensubject
PhysicsParticle physicsChiral perturbation theoryPhysics and Astronomy (miscellaneous)Nuclear Theory010308 nuclear & particles physicsNuclear TheoryBremsstrahlungCompton scatteringOrder (ring theory)FOS: Physical sciencesObservable01 natural sciencesBaryonNuclear Theory (nucl-th)High Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)0103 physical sciencesNuclear Experiment (nucl-ex)010306 general physicsNucleonNuclear ExperimentEngineering (miscellaneous)Nuclear Experimentdescription
The nucleon generalized polarizabilities (GPs), probed in virtual Compton scattering (VCS), describe the spatial distribution of the polarization density in a nucleon. They are accessed experimentally via the process of electron-proton bremsstrahlung ($ep\to ep\gamma$) at electron-beam facilities, such as MIT-Bates, CEBAF (Jefferson Lab), and MAMI (Mainz). We present the calculation of the nucleon GPs and VCS observables at next-to-leading order in baryon chiral perturbation theory (B$\chi$PT), and confront the results with the empirical information. At this order our results are predictions, in the sense that all the parameters are well-known from elsewhere. Within the relatively large uncertainties of our calculation we find good agreement with the experimental observations of VCS and the empirical extractions of the GPs. We find large discrepancies with previous chiral calculations---all done in heavy-baryon $\chi$PT (HB$\chi$PT)---and discuss the differences between B$\chi$PT and HB$\chi$PT responsible for these discrepancies.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2017-02-21 |