Cosmic-ray anisotropies observed by the ARGO-YBJ experiment

The ARGO-YBJ experiment is a full coverage EAS array sensitive to cosmic rays with energy threshold of few hundreds GeV. With all data recorded from November 2007 to May 2011 (about 2 x 10(11) events) we studied the declination region delta similar to -15 degrees-75 degrees looking for few-degree anisotropies at TeV energies. In this paper we report the observation of several few-degree anisotropy regions in the arrival direction of cosmic rays. The observation is carried out with high significance (up to 14 standard deviations) and unprecedented detail. The excess relative intensity with respect to the isotropic flux extends up to 10(-3). In the hypothesis that the excess is made of protons, the maximum occurs for energies around 10 TeV. Such a low value suggests the presence of unknown features of the magnetic fields which the charged cosmic rays propagate through, as well as potential contributions of nearby sources to the total flux of cosmic rays. (C) 2012 Elsevier B.V. All rights reserved.