Cosmic-ray muon flux at Canfranc Underground Laboratory

Residual flux and angular distribution of high-energy cosmic muons have been measured in two underground locations at the Canfranc Underground Laboratory (LSC) using a dedicated Muon Monitor. The instrument consists of three layers of fast scintillation detector modules operating as 352 independent pixels. The monitor has a flux-defining area of 1 m${}^2$ and covers all azimuth angles, and zenith angles up to 80${}^{\text{°}}$. The measured integrated muon flux is (5.26±0.21)×10${}^{\text{â}\text{ˆ}\text{’}3}$ m${}^{\text{â}\text{ˆ}\text{’}2}$s${}^{\text{â}\text{ˆ}\text{’}1}$ in the Hall A of the LAB2400 and (4.29±0.17)×10${}^{\text{â}\text{ˆ}\text{’}3}$ m${}^{\text{â}\text{ˆ}\text{’}2}$s${}^{\text{â}\text{ˆ}\text{’}1}$ in LAB2500. The angular dependence is consistent with the known profile and rock density of the surrounding mountains. In particular, there is a clear maximum in the flux coming from the direction of the Rioseta valley.