Detectability of Upgoing Sleptons

Some supersymmetric models predicted long lived charged sleptons. Following Albuquerque, Burdman and Chacko \cite{albu}, we consider an exact process where the $\widetilde{\tau}$, the supersymmetry partner of $\tau$ lepton, are produced inside the earth by collisions of high energy neutrinos with nucleons. We detailedly investigate the possible signals of upgoing $\widetilde{\tau}$ by comparing with the background muons where atmospheric neutrino flux is taken into account. The realistic spectra shows that km-scale experiments could see as many as 69 events a year by using the Waxman-Bahcall limit on the extraterrestrial neutrino flux.