Superscaling of non-quasielastic electron-nucleus scattering

TL;DR

This paper investigates the superscaling behavior of electron-nucleus scattering above the quasielastic peak, focusing on the Delta resonance region, by analyzing high-quality Carbon 12 data and comparing it with a scaling-based model.

Contribution

It introduces a method to analyze non-quasielastic cross sections by subtracting quasielastic contributions and explores scaling violations and meson-exchange current effects.

Findings

Residual cross sections align with the scaling-based model

Scaling violations are observed above the quasielastic peak

A potential method to isolate meson-exchange current effects

Abstract

The present study is focused on the superscaling behavior of electron-nucleus cross sections in the region lying above the quasielastic peak, especially the region dominated by electroexcitation of the Delta. Non-quasielastic cross sections are obtained from all available high-quality data for Carbon 12 by subtracting effective quasielastic cross sections based on the superscaling hypothesis. These residuals are then compared with results obtained within a scaling-based extension of the relativistic Fermi gas model, including an investigation of violations of scaling of the first kind in the region above the quasielastic peak. A way potentially to isolate effects related to meson-exchange currents by subtracting both impulsive quasielastic and impulsive inelastic contributions from the experimental cross sections is also presented.