Nuclear binding energy and transverse momentum imbalance in neutrino-nucleus reactions

TL;DR

This study introduces new kinematic imbalance observables in neutrino-nucleus interactions that are sensitive to nuclear effects like Fermi motion and binding energy, aiding in improved modeling and neutrino energy reconstruction.

Contribution

The paper presents novel transverse momentum imbalance observables in neutrino interactions, revealing limitations of existing models and demonstrating the impact of binding energy corrections.

Findings

Fermi gas models cannot fully describe the data features.

Binding energy corrections improve model-data agreement.

Hints of proton left-right asymmetry observed.

Abstract

We have measured new observables based on the final state kinematic imbalances in the mesonless production of $\nu_\mu+A\rightarrow\mu^-+p+X$ in the $\text{MINER}\nu\text{A}$ tracker. Components of the muon-proton momentum imbalances parallel ($\delta p_\mathrm{Ty}$) and perpendicular($\delta p_\mathrm{Tx}$) to the momentum transfer in the transverse plane are found to be sensitive to the nuclear effects such as Fermi motion, binding energy and non-QE contributions. The QE peak location in $\delta p_\mathrm{Ty}$ is particularly sensitive to the binding energy. Differential cross sections are compared to predictions from different neutrino interaction models. The Fermi gas models presented in this study cannot simultaneously describe features such as QE peak location, width and the non-QE events contributing to the signal process. Correcting the GENIE's binding energy implementation according to theory causes better agreement with data. Hints of proton left-right asymmetry are observed in $\delta p_\mathrm{Tx}$. Better modeling of the binding energy can reduce bias in neutrino energy reconstruction and these observables can be applied in current and future experiments to better constrain nuclear effects.