Extraction of Neutrino Flux with the Low $\nu$ Method at MiniBooNE Energies

TL;DR

This paper applies the low-$ u$ method to extract the neutrino flux at MiniBooNE energies, validating the flux and analyzing the axial form factor with different nuclear models, resulting in refined axial mass estimates.

Contribution

It demonstrates the use of the low-$ u$ method for flux extraction at MiniBooNE energies and explores the impact of nuclear effects on axial form factor measurements.

Findings

Flux extracted from low-$ u$ cross sections matches the nominal MiniBooNE flux.

Axial mass $M_A$ is approximately 1.41 GeV without nuclear effects.

Including nuclear transverse enhancement, $M_A$ reduces to about 1.10 GeV.

Abstract

We describe the application of the `low-$\nu$' method to the extraction of the neutrino flux at MiniBooNE energies. As an example, we extract the relative energy dependence of the flux from published MiniBooNE quasielastic scattering cross sections with $\nu < 0.2$ GeV and $\nu < 0.1$ GeV (here $\nu$ is the energy transfer to the target). We find that the flux extracted from the `low-$\nu$' cross sections is consistent with the nominal flux used by MiniBooNE. We fit the MiniBooNE cross sections over the entire kinematic range to various parametrizations of the axial form factor. We find that if the overall normalization of the fit is allowed to float within the normalization errors, the extracted values of the axial vector mass are independent of the flux. Within the Fermi gas model, the $Q^2$ distribution of the MiniBooNE data is described by a standard dipole form factor with $M_A=1.41\pm0.04$ GeV. If nuclear transverse enhancement in the vector form factors is accounted for, the data are best fit with a modified dipole form factor with $M_A=1.10\pm 0.03$ GeV.