Observation of the cosmic ray large-scale anisotropy with the ARGO-YBJ experiment

This paper reports on the observation of the sidereal large-scale anisotropy of cosmic rays using the ARGO-YBJ data collected from 2008 January to 2012 December. The anisotropy is investigated within a wide energy range from 4 to 520 TeV. Below 100 TeV, the anisotropy is dominated by two wide regions, the so-called "tail-in" and "loss-cone" features. The maximum value of the anisotropy is around 7 TeV. No noticeable variation of cosmic-ray anisotropy with solar activity is observed during the 5 years even though the solar activity varied from near minimum to maximum. Above 100 TeV, a dramatic change of the morphology is confirmed. The physical implications of these results are also discussed.