# Impact of cross section uncertainties on NOvA oscillation analyses

## TL;DR

This paper investigates how uncertainties in neutrino interaction cross section models, especially those in GENIE, impact the precision of oscillation measurements in the NOvA experiment and explores mitigation strategies.

## Contribution

It analyzes the effects of cross section model uncertainties on NOvA's oscillation results and proposes analysis methods to reduce their impact.

## Key findings

- Cross section uncertainties significantly affect oscillation parameter estimates.
- Using near detector data helps mitigate model-related uncertainties.
- Modifications to GENIE influence the predicted spectra and analysis outcomes.

## Abstract

The NOvA experiment is an off-axis long-baseline neutrino oscillation experiment measuring $\nu_{\mu}$ disappearance and $\nu_{e}$ appearance in a $\nu_{\mu}$ beam originating at Fermilab. Oscillations are observed in the far detector relative to measurements made in the near detector, with a full simulation of the beam line and detectors being used to perform extrapolation between them. The neutrino simulation uses the GENIE event generator, which contains implementations of numerous theoretical neutrino interaction models applied to a variety of nuclear targets. However, recent data, recent reanalysis of extant data, and continued development of theoretical models have brought to light deficiencies in the default GENIE cross section model, which informs the predicted spectra used to infer oscillation parameters. We explore how uncertainties in this model, together with modifications to GENIE version 2.12.2 based on external information and NOvA Near Detector (ND) data, affect NOvA's oscillation parameter inferences. We also discuss how these uncertainties can be mitigated by judicious analysis design, including usage of the ND data.