MINOS Observations of Shadowing in the Muon Flux Underground

TL;DR

This paper reports the detection of the sun and moon shadows in underground muon flux using the MINOS detector, demonstrating the detector's angular resolution and pointing accuracy with high significance.

Contribution

First observation of solar and lunar shadowing effects in underground muon flux with detailed angular resolution analysis.

Findings

Detected sun and moon shadows with high significance

Measured the detector's angular resolution as 0.34 degrees

Determined the detector's pointing accuracy as 0.3 degrees

Abstract

A high significance observation of two muon signals, the shadow of the sun and moon, have been seen by the \unit[5.4]{kt} MINOS Far Detector, at a depth of \unit[2070]{mwe}. The distribution of angular separation of muons near the moon was well described by a Gaussian, which was used to determine the angular resolution ($0.34^{\circ}\pm0.07^{\circ}$) and pointing ($0.3^{\circ}\pm0.05^{\circ}$) of the detector.