Implementation of an upward-going muon trigger for indirect dark matter searches at the NO$\nu$A far detector

TL;DR

This paper discusses the development of an upward-going muon trigger at NO$ u$A, enabling the detector to perform indirect dark matter searches by identifying muons from potential WIMP annihilations, despite high cosmic ray backgrounds.

Contribution

The paper presents the design and status of a novel upward-going muon trigger for NO$ u$A, aimed at enhancing its capability for indirect dark matter detection.

Findings

Trigger demonstrates potential for effective cosmic ray background rejection.

The detector's energy resolution supports low-mass WIMP searches.

Status update on trigger implementation and performance.

Abstract

The NO$\nu$A collaboration has constructed a 14,000 ton, fine-grained, low-Z, total absorption tracking calorimeter at an off-axis angle to an upgraded NuMI neutrino beam. This detector, with its excellent granularity and energy resolution and relatively low-energy neutrino thresholds, was designed to observe electron neutrino appearance in a muon neutrino beam, but it also has unique capabilities suitable for more exotic efforts. In fact, if an efficient upward-going muon trigger with sufficient cosmic ray background rejection can be demonstrated, NO$\nu$A will be capable of a competitive indirect dark matter search for low-mass WIMPs. The cosmic ray muon rate at the NO$\nu$A far detector is about 100 kHz and provides the primary challenge for triggering and optimizing such a search analysis. The status of the NO$\nu$A upward-going muon trigger is presented.