Basic features of the pion valence-quark distribution function
The impulse-approximation expression used hitherto to define the pion’s valence-quark distribution function is flawed because it omits contributions from the gluons which bind quarks into the pion. A corrected leading-order expression produces the model-independent result that quarks dressed via the...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2014 |
| País: | España |
| Institución: | Universidad de Huelva (UHU) |
| Repositorio: | Arias Montano. Repositorio Institucional de la Universidad de Huelva |
| Idioma: | inglés |
| OAI Identifier: | oai:ariasmontano.uhu.es:10272/18417 |
| Acceso en línea: | http://hdl.handle.net/10272/18417 |
| Access Level: | acceso abierto |
| Palabra clave: | Deep inelastic scattering Drell–Yan process Dynamical chiral symmetry breaking Dyson–Schwinger equations π-meson Parton distribution functions |
| Sumario: | The impulse-approximation expression used hitherto to define the pion’s valence-quark distribution function is flawed because it omits contributions from the gluons which bind quarks into the pion. A corrected leading-order expression produces the model-independent result that quarks dressed via the rainbow–ladder truncation, or any practical analogue, carry all the pion’s light-front momentum at a characteristic hadronic scale. Corrections to the leading contribution may be divided into two classes, responsible for shifting dressed-quark momentum into glue and sea-quarks. Working with available empirical information, we use an algebraic model to express the principal impact of both classes of corrections. This enables a realistic comparison with experiment that allows us to highlight the basic features of the pion’s measurable valence-quark distribution, qπ (x); namely, at a characteristic hadronic scale, qπ (x) ∼ (1 − x)2 for x 0.85; and the valence-quarks carry approximately two-thirds of the pion’s light-front momentum. |
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