Enhanced search for neutral current $\Delta$ radiative single-photon production in MicroBooNE

TL;DR

This paper presents an updated search for neutral current $elta$(1232) baryon production and decay in MicroBooNE, using two reconstruction methods, and excludes the hypothesis that this process explains the MiniBooNE anomaly at 94.4% confidence level.

Contribution

The study introduces a dual reconstruction approach with Pandora and Wire-Cell to improve sensitivity in detecting $elta$ radiative decay events in MicroBooNE data.

Findings

Data exclude the hypothesis that NC $elta ightarrow N \u03b3$ explains the MiniBooNE anomaly at 94.4% CL.

Events with and without final state protons are decoupled, showing different compatibility with excess explanations.

The analysis constrains the possible origins of the MiniBooNE excess in terms of $elta$ production.

Abstract

We report results from an updated search for neutral current (NC) resonant $\Delta$(1232) baryon production and subsequent $\Delta$ radiative decay (NC $\Delta\rightarrow N \gamma$). We consider events with and without final state protons; events with a proton can be compared with the kinematics of a $\Delta(1232)$ baryon decay, while events without a visible proton represent a more generic phase space. In order to maximize sensitivity to each topology, we simultaneously make use of two different reconstruction paradigms, Pandora and Wire-Cell, which have complementary strengths, and select mostly orthogonal sets of events. Considering an overall scaling of the NC $\Delta\rightarrow N \gamma$ rate as an explanation of the MiniBooNE anomaly, our data exclude this hypothesis at 94.4% CL. When we decouple the expected correlations between NC $\Delta\rightarrow N \gamma$ events with and without final state protons, and allow independent scaling of both types of events, our data exclude explanations in which excess events have associated protons, and do not exclude explanations in which excess events have no associated protons.