Mainz 2014 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 58: Neutrinoastronomie 2

T 58.7: Talk

Tuesday, March 25, 2014, 18:15–18:30, P13

On the relevance of the electron-to-proton ratio for high-energy neutrino fluxes — •Lukas Merten and Julia Tjus — Ruhr-Universität Bochum, Fakultät für Physik und Astronomie, Institut für Theoretische Physik, 44780 Bochum, Germany

The calculation of the cosmic ray spectrum of a certain source is very difficult as direct observation is not possible in most cases. A common techniques uses the chargeless synchrotron radiation produced in leptonic processes: From the synchrotron measurement, the electron spectrum can be derived. Thus, if the proton-electron luminosity ratio is known, it is possible to estimate the proton spectrum from leptonic data.

In most literature this ratio is assumed to be approximately K≈10−100. Using more detailed calculations it turned out that even for slightly different spectral indices, the exact value deviates by orders of magnitude from the conventional ratio with increasing energies. Furthermore approximations for the exact values with respect to the different spectral indices were derived. These energy-dependent lowest order simplifications deviate less than a few percent from exact results.

These new results are of particular importance for different neutrino flux models, in which the observed synchrotron radiation is used to estimate the flux of neutrinos from hadronic interactions. This flux usually scales with ∝ K, and therefore, the exact choice of K is very important for those calculations. In this talk, we discuss the consequences of our calculations for neutrino flux predictions and the interpretation of model-dependent neutrino flux limits presented by IceCube.