Speaker
Tom Paul
(Northeastern University, USA)
Description
The Pierre Auger Observatory was designed to make precise measurements of cosmic ray air showers induced by the highest energy cosmic particles. The aparatus consists of about 1600 water Cherenkov tanks distributed over an area of some 3000 square kilometers, all of which are overlooked by 24 fluorescence telescopes. The instrument has already provided us with the most detailed energy spectrum measurement at the highest energies, information on the primary
composition, and hints of ansisotropy in the arrival directions of the highest energy events. The aparatus provides a means to study not only hadron and photon induced showers, but also the showers which may be produced by untrahigh energy neutrinos interacting in the atmosphere or in the Earth. Interestingly, it may be possible to uncover non-perturbative physics by comparing the rate of nearly horizontal showers generated by deeply penetrating neutrinos to that of up-going showers produced by neutrinos skimming the Earth's surface. Though the techique is agnostic regarding the hypothetical physics underpinning such signatures, an observation could have bearing on our picture of how the baryon asymmetry of the universe was created.
