1 0 Ju l 2 01 8 Deep inelastic e − τ and μ − τ conversion in the NA 64 experiment at the CERN SPS

Sergei Gninenko, Sergey Kovalenko, Serguei Kuleshov, Valery E. Lyubovitskij, 3, 4, 5 and Alexey S. Zhevlakov Institute for Nuclear Research, 117312 Moscow, Russia Departamento de F́ısica y Centro Cient́ıfico Tecnológico de Valparáıso-CCTVal, Universidad Técnica Federico Santa Maŕıa, Casilla 110-V, Valparáıso, Chile Institut für Theoretische Physik, Universität Tübingen, Kepler Center for Astro and Particle Physics, Auf der Morgenstelle 14, D-72076, Tübingen, Germany Department of Physics, Tomsk State University, 634050 Tomsk, Russia Tomsk State Pedagogical University, 634061 Tomsk, Russia Matrosov Institute for System Dynamics and Control Theory SB RAS, Lermontov str. 134, 664033, Irkutsk, Russia