Speaker
Prof.
Subir Sarkar
(University of Oxford)
Description
Cosmogenic neutrinos with energy up to ~10^{11} GeV originate from photo-
hadronic interactions of UHECR protons with the CMB and the accompanying EM
cascades generate a diffuse gamma-ray background in the GeV-TeV region. Thus
Fermi-LAT measurements of the extragalactic gamma-ray flux constrain the
cosmogenic flux and, indirectly, the UHECR source spectrum and its cosmological
evolution in conjunction with air shower data from Auger and HiRes. The best-fit flux
is still within reach of experiments such as ANITA, Auger and IceCube, however if the
primary UHECRs are heavy nuclei rather than protons then the neutrino flux will be
even smaller. Nevertheless there is a case for constructing even larger detectors
given the potential for probing non-perturbative QCD as well as BSM physics by
sudying deep inelastic scattering of such high energy neutrinos.
Primary author
Prof.
Subir Sarkar
(University of Oxford)
