arXiv subjects

K. Payet

Publications and source records attributed to K. Payet.

3 recordsLinked to original sources

arXiv2009

Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector

Cosmic rays extensive air showers (EAS) are associated with transient radio emission, which could provide an efficient new detection method of high energy cosmic rays, combining a calorimetric measurement with a high duty cycle. The CODALEMA experiment, installed at the Radio Observatory in Nancay, France, is investigating this phenomenon in the 10^17 eV region. One challenging point is the understanding of the radio emission mechanism. A first observation indicating a linear relation between the electric field produced and the cross product of the shower axis with the geomagnetic field direction has been presented (B. Revenu, this conference). We will present here other strong evidences for this linear relationship, and some hints on its physical origin.

astro-ph.HE↗

arXiv2009

The propagation of ultra-high energy tau leptons and neutrinos while skimming the Earth

The detection of Earth-skimming tau neutrinos has turned into a very promising strategy for the observation of UHE cosmic neutrinos. The sensitivity of this channel crucially depends on the parameters of the propagation of the tau neutrino (and the tau lepton) through the terrestrial crust, which governs the flux of emerging tau leptons that can be detected. This propagation problem is usually treated in a simplified framework where several effects are neglected, e.g. the possibility of multiple regenerations of the tau neutrino, the weak interactions of the tau lepton, as well as the stochastic nature of its energy losses. We discuss here the validity of such approximations by studying the propagation in standard rock of tau leptons and neutrinos with both mono-energetic and power-law spectra. We also investigate the impact of such simplifications in non-standard scenarios for the neutrino-nucleon interactions as well as for the tau energy losses.

hep-ph↗

arXiv2009

Geomagnetic origin of the radio emission from cosmic ray induced air showers observed by CODALEMA

The new setup of the CODALEMA experiment installed at the Radio Observatory in Nancay, France, is described. It includes broadband active dipole antennas and an extended and upgraded particle detector array. The latter gives access to the air shower energy, allowing us to compute the efficiency of the radio array as a function of energy. We also observe a large asymmetry in counting rates between showers coming from the North and the South in spite of the symmetry of the detector. The observed asymmetry can be interpreted as a signature of the geomagnetic origin of the air shower radio emission. A simple linear dependence of the electric field with respect to vxB is used which reproduces the angular dependencies of the number of radio events and their electric polarity.

astro-ph.HE↗