A study of correlation between IceCube neutrino events and Ultra high energy cosmic rays

Sources for cosmic neutrino events detected by the IceCube Neutrino Observatory with energy above 30 TeV are hard to find due to their poor angular resolutions. Ultrahigh-energy cosmic rays (UHECRs) are detected with better angular resolutions above 100 EeV energies and can be used to check if the same astrophysical sources are responsible for producing both neutrinos and UHECRs. We test the correlation of UHECR data of the Pierre Auger Observatory, Telescope Array and past cosmic-ray experiments with IceCube neutrino events using statistical methods which emphasize invariant quantities. We find that the arrival directions of the 3yr IceCube detected cosmic neutrinos are correlated with > 100 EeV UHECR arrival directions at confidence level 90% . In our recent approach we have tried to find a correlation of the 4 yr IceCube detected High-Energy Starting Events (HESE) neutrino events with UHECRs from PAO and TA. We found more than 3s correlation for PAO only and TA+PAO UHECRs events > 100 EeV.