Measurement of neutral-current $K^+$ production by neutrinos using MINERvA

TL;DR

This paper measures the production of neutral-current $K^+$ particles by neutrinos in the MINERvA experiment, providing data crucial for understanding backgrounds in proton decay searches and comparing predictions from different neutrino interaction models.

Contribution

It presents the first measurement of neutral-current $K^+$ production differential cross sections and compares these results with predictions from NEUT and GENIE generators.

Findings

Observed excess of events at low hadronic energy compared to NEUT

Good agreement with GENIE cross section predictions

Detected a 2σ deficit of photons from $C0^0$ decay relative to GENIE

Abstract

Neutral-current production of $K^{+}$ by atmospheric neutrinos is a background in searches for the proton decay $p \rightarrow K^{+} \bar{\nu}$. Reactions such as $\nu p \rightarrow \nu K^{+} \Lambda$ are indistinguishable from proton decays when the decay products of the $\Lambda$ are below detection threshold. Events with $K^{+}$ are identified in MINERvA by reconstructing the timing signature of a $K^{+}$ decay at rest. A sample of 201 neutrino-induced neutral-current $K^{+}$ events is used to measure differential cross sections with respect to the $K^{+}$ kinetic energy, and the non-$K^{+}$ hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of the NEUT event generator. Good agreement is observed with the cross section prediction of the GENIE generator. A search for photons from $\pi^{0}$ decay, which would veto a neutral-current $K^{+}$ event in a proton decay search, is performed, and a 2$\sigma$ deficit of detached photons is observed relative to the GENIE prediction.