  The origin of ultra-high energy cosmic rays (UHECRs) and neutrinos is still a
mystery. Hadronic acceleration theory suggests that they should originate in
the same sources (astrophysical or cosmological), together with gamma-rays.
While gamma-rays have been linked to astrophysical sources, no point source of
UHECRs or neutrinos have been found so far. In this paper, the multimessenger
combination of UHECRs and neutrinos as a new approach to the high energy
particle point source search is suggested. A statistical method for
cross-correlation of UHECR and neutrino data sets is proposed. By obtaining the
probability density function of number of neutrino events within chosen angular
distance from observed UHECRs, the number of neutrino events in the vicinity of
observed UHECRs, necessary to claim a discovery with a chosen significance, can
be calculated. Different angular distances (bin sizes) are considered due to
the unknown deflection of cosmic rays in galactic and intergalactic magnetic
fields. Possible observed correlation of the arrival directions of UHECRs and
neutrinos would provide a strong indication of hadronic acceleration theory.
Correlation of both types of messengers with the location of certain sets of
observed astrophysical objects would indicate sites of acceleration. Any
systematic offset in arrival directions between UHECRs and neutrinos may shed
more light on magnetic field deflection of cosmic rays.
