Ultra-high energy neutrinos from charm production: atmospheric and astrophysical origins

by Rikard Enberg (Uppsala University)

Thursday 20 Oct 2016, 15:15 → 16:15 Europe/Stockholm

12167 (Ångström)

Charged particles are accelerated to ultra-high energies in cosmic sources, which gives rise to fluxes of both cosmic rays and neutrinos. Neutrinos are produced in such sources when the accelerated beams collide with the surrounding material or with photons. The charged particles themselves can be emitted as cosmic rays. Neutrinos are also produced when such ultra-high energy cosmic rays collide with Earth's atmosphere, which leads to a flux of atmospheric neutrinos. I will discuss recent calculations of both atmospheric and astrophysical neutrino fluxes where the neutrinos arise from decay of charm quarks produced in the collisions. We have recently updated our 2008 prediction for the atmospheric neutrino flux with improved theoretical calculations, including the latest parton distribution functions. We have also for the first time taken nuclear shadowing into account, and we have validated our calculations against LHC data. Moreover, we now use newer measurements of the cosmic ray flux. We find a substantial reduction in the predicted neutrino flux from charm. I will also discuss our model for astrophysical neutrinos from charm production in slow-jet supernovae, which provides a possible explanation for the observed IceCube neutrinos. Finally, I will discuss our calculation of the neutrino flux from cosmic rays that collide with the Sun

Slides Enberg-UU-seminar-2016.pdf