Progress in the Search for Dark Matter Using Upward-going Muons in NOvA
2017 February 06
2017 April 19
The NOvA 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, energy resolution and relatively low-energy neutrino thresholds, was designed to measure $\nu_\mu \rightarrow \nu_e$ neutrino appearance. These characteristics combined with the detector's timing resolution, continuous readout structure, and placement on the surface of the Earth make it ideal for use as a neutrino telescope. In order to operate in this telescope mode, NOvA experiment has developed a highly efficient upward-going muon trigger which is able to achieve a background suppression rate of $10^4$ within the experiment's DAQ systems which is then increased by an additional factor of $10^6$ in the offline to fully suppress the flux of downward going cosmics rays. The trigger efficiencies and rejection capabilities allow NOvA to be competitive in indirect dark matter searches for low-mass WIMPs. We present initial progress and results for an upward going muon analysis using data-driven background estimations that include signal and sideband region validation, as well as timing based directional track reconstruction. In addition we present results from the analysis of muon depletion corresponding to the celestial position of the moon, as a technique to determine an upper limits on the pointing resolution of the NOvA detector.