New results on the numu-nutau oscillation search with the CHORUS detector

Abstract

The present results on the $\numtonut$ oscillation search by the CHORUS experiment at CERN are summarised. A fraction of the neutrino interactions collected in 1994-1995-1996 by the CHORUS experiment has been analysed, searching for ${\nu }_{\tau }$ charged current interactions followed by the $\tau$ lepton decay into a negative hadron or into a muon. A sample of 68,156 events with an identified final state muon and 7,206 events without an identified muon in the final state have been located in the emulsion target. Within the applied cuts, no ${\nu }_{\tau }$ candidate has been found. This result leads to a 90% C.L. limit $P(\numtonut)< 6.0\cdot 10^{-4}$ on the mixing probability.

5 pages, two figures