Regresar

Erratun: Search for ultrahigh energy neutrinos in highly inclined events at the Pierre Auger Observatory (Physical Review D-Particles, Fields, Gravitation and Cosmology (2011 …

Abstract:

Neutrinos play a key role in the understanding of the origin of ultra high energy cosmic rays (UHECRs). Their observation should open a new window to the universe since they can give information on regions that are otherwise hidden by large amounts of matter in the field of view. Moreover, neutrinos are not deviated by magnetic fields and would point back to their sources. In the EeV range, neutrinos are expected to be produced in the same sources where UHECRs are thought to be accelerated, as well as during the propagation of UHE-CRs through the cosmic microwave background (CMB) radiation [1]. The latter are called cosmogenic neutrinos and their presence is expected if the UHECRs above the spectral cut-off reported in [2] contain a significant fraction of protons [3–8]. There are many current programs to search for high energy neutrinos with dedicated experiments [9–11]. Although the primary goal of the Pierre Auger Observatory Surface (SD) and Fluorescence Detectors (FD) is to detect UHECRs, UHE neutrinos (UHEνs) can also be identified and limits to the diffuse flux of UHEνs in the EeV range and above have been set using earlier Auger data [12–14]. Earth-skimming τ neutrinos are expected to be observed through the detection of showers induced by the decay of emerging τ leptons which are created by ντ interactions in the Earth [15]. Using this mechanism for data collected from 1 January 2004 until 30 April 2008, an upper limit was set: E2