Nuclear Target Cross Section Ratios at MINERvA

TL;DR

This paper presents the first direct measurements of how neutrino scattering cross sections vary across different nuclei, revealing nuclear effects that challenge existing models.

Contribution

It provides novel experimental data on nuclear dependence in neutrino interactions, highlighting discrepancies with current theoretical models and event generators.

Findings

Depletion of cross section ratios at low Bjorken x

Enhancement of ratios at large x with increasing nucleon number

Data trends not reproduced by GENIE or other models

Abstract

Measurements of $\nu_{\mu}$ inclusive charged-current cross section ratios on carbon, iron, and lead relative to scintillator are presented. Data for the analysis were collected by the fine-grained MINERvA detector in the NuMI beamline at Fermilab. This is the first direct measurement of nuclear dependence in neutrino scattering. The ratios show a depletion at low Bjorken $x$ and enhancement at large $x$, both of which increase with the nucleon number of the target. The data exhibit trends not found in GENIE, a standard neutrino-nucleus event generator, or alternative models of nuclear modification to inelastic structure functions.