Relativistic effects in electromagnetic nuclear responses in the quasi-elastic delta region

Abstract

A new non-relativistic expansion in terms of the nucleon's momentum inside nuclear matter of the current for isobar electro-excitation from the nucleon is performed. Being exact with respect to the transferred energy and momentum, this yields new current operators which retain important aspects of relativity not taken into account in the traditional non-relativistic reductions. The transition current thus obtained differs from the leading order of the traditional expansion by simple multiplicative factors. These depend on the momentum and energy transfer and can be easily included together with relativistic kinematics in non-relativistic, many-body models of isobar electro-excitation in nuclei. The merits of the new current are tested by comparing with the unexpanded electromagnetic nuclear responses in the isobar peak computed in a relativistic Fermi gas framework. The sensitivity of the relativistic responses to the isobar's magnetic, electric and Coulomb form factors and the finite width of the isobar is analyzed.

26 pages plus 6 figures

References in corpus (8)

• Many Body approach to the inclusive $(e,e^{\prime })$ reaction from the quasielastic to the $\Delta$ excitation region
• Relativistic Effects in Electromagnetic Meson-Exchange Currents for One-Particle Emission Reactions
• Coherent Photoproduction of Pions on Spin-Zero Nuclei in a relativistic, non-local Model
• Inclusive quasielastic scattering of polarized electrons from polarized nuclei
• Mainz "measurement" of the $E2/M1$ ratio in the $N-\Delta$ transition
• E2/M1 ratio from the Mainz $p(\vec{\gamma },p){\pi }^0$ data
• Nuclear Response in Electron Scattering at High Momentum Transfer
• On the role of the $\Delta (1232)$ on the transverse nuclear response in the $(e,e^{\prime })$ reaction

Cited by in corpus (16)

• Using Electron Scattering Superscaling to predict Charge-changing Neutrino Cross Sections in Nuclei
• Extended Superscaling of Electron Scattering from Nuclei
• Gauge and Lorentz invariant one-pion exchange currents in electron scattering from a relativistic Fermi gas
• Inelastic electron-nucleus scattering and scaling at high inelasticity
• Final-state interactions and superscaling in the semi-relativistic approach to quasielastic electron and neutrino scattering
• Electron- versus neutrino-nucleus scattering
• Superscaling analysis of inclusive electron scattering and its extension to charge-changing neutrino-nucleus cross sections beyond the relativistic Fermi gas approach
• Delta-isobar relativistic meson exchange currents in quasielastic electron scattering
• Relativistic pionic effects in quasielastic electron scattering
• Nuclear response functions for the N-N*(1440) transition
• Influence of nucleonic motion in Relativistic Fermi Gas inclusive responses
• RPA quasi-elastic responses in infinite and finite nuclear systems
• The generalised relativistic Lindhard functions
• Contrasting N Delta and N N parity-violating asymmetries in nuclei
• The role of the $\Delta$(1232) on the longitudinal response in the inclusive electron scattering reaction
• Superscaling of non-quasielastic electron-nucleus scattering