Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
In the model of quintessino as the dark matter particle, the dark matter and dark energy are unified in one superfield, where the dynamics of the Quintessence drives the Universe acceleration and its superpartner, quintessino, makes up the dark matter of the Universe. This scenario predicts the existence of long-lived tau as the next lightest supersymmetric particle. In this paper we study the possibility of detecting tau produced by the high energy cosmic neutrinos interacting with the earth matter. By a detailed calculation we find that the event rate is one to several hundred per year at a detector with an effective area of 1 km(2). The study in this paper can be also applied to models of gravitino or axino dark matter particles.