A. Mariano
Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, cc.67, 1900 La Plata, Argentina
Recibido el 7 de enero de 2005
Aceptado el 30 de enero de 2005
Abstract
]]> Electron scattering by nuclei at high momentum transfers is studied within the Fermi smearing approximation (FSA), where binding effects on the struck nucleon are introduced via the relativistic mean field theory (MFT). The model naturally preserves electromagnetic current conservation, since the response tensor for an off–shell nucleon conserves the same form that for a free one but with an effective mass. Different parameterizations for the inelastic nucleon structure function, are used. We also analyze the behavior of the experimental nuclear response in terms of the scaling variable y associated to the model. Recent CEBAF data for the inclusive cross section of 4.05 GeV electrons on 56Fe, are well reproduced for all measured geometries. The theoretical scaling function describes properly the trend of the experimental data, except at high values of Q2 and large negative values of y. Future improvements to the model are proposed.Keywords: Inelastic electron scattering; Relativistic scattering; Scaling laws.
Resumen
La dispersión de electrones a altas transferencias de impulso es estudiada usando la distribución de momentos de un nucleón, mientras que los efectos de ligadura se introducen mediante la teoría de campo medio relativista. El modelo naturalmente conserva la corriente electromagnética, ya que el tensor respuesta para un nucleón fuera de la capa de masas mantiene la misma forma que la de un nucleón libre pero con una masa efectiva. Diferentes parametrizaciones de la respuesta inelástica del nucleón son usadas. También analizamos la respuesta nuclear experimental en términos de la variable y de escaleamiento asociada al modelo. Los datos recientes del CEBAF para la sección eficaz inclusiva de electrones de 4.05 GeV sobre B6Fe, son bien reproducidos para todas las geometrías medidas. La función de escaleamiento teórica describe propiamente la tendencia de los datos experimentales, excepto a valores altos de Q2 y valores negativos de y. Se proponen futuras mejoras al modelo.
Descriptores: Dispersión inelástica de electrones; Dispersión relativista; Leyes de escalamiento.
PACS: 25.30.Dh; 11.80–m; 89.75.Da
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]]>Acknowledgements
The work of A. Mariano was supported by Conicet (Argentina).
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