Measurement of Inclusive Charged-Current $\bar{\nu}_{\mu}$ Scattering on C, CH, Fe, and Pb at $\langle E_{\bar{\nu}}\rangle \sim$ 6 GeV with MINERvA

TL;DR

MINERvA measured inclusive charged-current antimuon neutrino cross sections on various nuclei at around 6 GeV, revealing discrepancies with models especially at low transverse momentum, highlighting nuclear effect modeling issues.

Contribution

First measurement of these cross sections on multiple nuclei and their ratios at ~6 GeV, providing critical data for nuclear effect modeling in neutrino interactions.

Findings

Cross section uncertainties are 5-10% for absolute measurements.

Ratios have 2-5% uncertainties, enabling precise comparisons.

Significant model discrepancies observed, especially at low $p_T$.

Abstract

We report MINERvA's first measurement of inclusive charged-current $\bar{\nu}_\mu$ cross sections on carbon, hydrocarbon, iron, and lead, and their ratios to the cross section on hydrocarbon, as functions of the antimuon transverse momentum, $p_{\mathrm{T}}$. Using a wide-band $\bar{\nu}_\mu$ beam with mean energy $\sim 6~\text{GeV}$, these measurements probe all interaction modes, including the transition from resonance production to deep-inelastic scattering. The total uncertainties are typically $5-10\%$ for the absolute cross sections and $2-5\%$ for the ratios. Comparisons with multiple neutrino interaction models reveal significant discrepancies in the $p_{\mathrm{T}}$ dependence, particularly for heavier nuclei. The disagreements are most pronounced at low $p_{\mathrm{T}}$ but extend across the full $p_{\mathrm{T}}$ range, indicating missing or mis-modelled nuclear effects.