Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

THE PIERRE AUGER COLLABORATION (VER M. PLATINO EN PUBLICACIÓN); MANUEL PLATINO

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Año: 2008 vol. 100 p. 1 - 14

0031-9007

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau-neutrinos $u_au$ that interact in the Earth´s crust. Tau leptons from $u_au$ charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 is used to place an upper limit on the diffuse flux of $u_au$ at EeV energies. Assuming an $E_u^{-2}$ differential energy spectrum the limit set at 90 % C.L. is $E_u^{2} mathrm{d}N_{u_au}/mathrm{d}E_{u} < 1.3 imes 10^{-7}$ GeV cm$^{-2}$ s$^{-1}$ sr$^{-1}$ in the energy range $2imes10^{17} mathrm{eV} < E_u < 2imes10^{19}$ eV.