Correlation between the UHECRs measured by the Pierre Auger Observatory and Telescope Array and neutrino candidate events from IceCube

¹ Département de physique nucléaire et corpusculaire, Université de Genève, 24 Quai Ernest Ansermet, 1211 Genève, Switzerland
² Centro Atómico Bariloche, Av. Bustillo 9500, S. C. de Bariloche 8400, Argentina
³ Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), Universités Paris 6 et Paris 7, CNRS-IN2P3, 4 place Jussieu, 75252 Paris, France
⁴ Karlsruhe Institute of Technology – Campus North – Institut fër Kernphysik, Karlsruhe, Germany and New York University, New York, USA
⁵ Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba, Japan
⁶ Service de Physique Théorique, Université Libre de Bruxelles, Boulevard du Triomphe (Campus de la Plaine), Ixelles 1050, Belgium

^a e-mail: Mohamed.Rameez@unige.ch
^b http://icecube.wisc.edu/collaboration/authors/current
^c http://www.auger.org/archive/authors_2015_12.html
^d http://www.telescopearray.org/index.php/research/collaborators

Published online: 11 April 2016

Abstract

We present the results of three searches for correlations between ultra-high energy cosmic ray events measured by Telescope Array and the Pierre Auger Observatory and high-energy neutrino candidate events from IceCube. Two cross-correlation analyses of ultra-high energy cosmic rays are done: one with 39 “cascades” from the IceCube “high-energy starting events” sample and the other one with 16 high-energy “tracks”. The angular separation between the arrival directions of neutrinos and UHECRs is scanned. The same events are also used in a separate search stacking the neutrino arrival directions and using a maximum likelihood approach. We assume that UHECR magnetic deflections are inversely proportional to the energy with values 3^∘, 6^∘ and 9^∘ at 100 EeV to account for the uncertainties in the magnetic field strength and UHECR charge. A similar analysis is performed on stacked UHECR arrival directions and the IceCube 4-year sample of through-going muon-track events that was optimized for neutrino point source searches.