Relation of muon flux local anisotropy with primary spectrum index

Muon hodoscope URAGAN allows to obtain the angular distribution of the muon flux. This distribution may be characterized by a vector of local anisotropy (the sum of the vectors of the particle arrival directions, normalized to the total number of muons). It was shown that annual variations in the vertical projection of the anisotropy vector A _Z are not related with changes in atmospheric conditions. The dependence of A _Z on the index of the primary particles spectrum γ was calculated for several zenith angle intervals with the help of simulation of generation and propagation of secondary cosmic ray particles through the atmosphere using the CORSIKA package. Experimental temporal series of the vertical projection of the local anisotropy A _Z for several intervals of zenith angles were obtained for 2007-2015. According to the obtained A _Z time series, annual and diurnal changes of Δ_γ were estimated. (paper)