Observation of cosmic ray anisotropy with GRAPES-3 Experiment

Large scale anisotropy of cosmic rays (CRs) in the TeV-PeV energy region has been reported by several experiments located in the Northern Hemisphereas well as by the IceCube, and its surface array IceTop at the South Pole. The GRAPES-3experiment in Ooty, India is designed to observe CRs in the energy range from a few TeV to over 10 PeV. Its near-equatorial location (11.4°N) provides a unique advantage for observations of CR anisotropy, overlapping with experiments in both the hemispheres. The GRAPES-3consists of a dense array of ~400 plastic scintillator detectors spread over an area of 25000 m2. It also contains a large area (560 m2) tracking muon detector which provides an excellent capability to discriminate γ-rays against CRs. It has recorded over 10 billion showers since its operation began in 2000. Measurement of CR anisotropy with a subset of this data is presented here.