Forward doubly-virtual Compton scattering off the nucleon in chiral perturbation theory. II. Spin polarizabilities and moments of polarized structure functions
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 spec...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2020 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/7267 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/7267 |
| Access Level: | acceso abierto |
| Palabra clave: | Electromagnetismo Física-Modelos matemáticos Teoría de los quanta 2202 Electromagnetismo 2210.23 Teoría Cuántica |
| Sumario: | 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. |
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