Speaker
Description
At the CERN SPS, the DsTau project has been proposed to study tau-neutrino production aiming at providing important information for future $\nu_\tau$ measurements. Precise measurement of the $\nu_\tau$ cross section would enable a search for new physics effects in $\nu_\tau$-nucleon CC interactions. It also has practical implications for neutrino oscillation experiments. The dominant source of $\nu_\tau$ is the sequential decay of $D_s$ mesons produced by proton interactions, whose uncertainty dominates current uncertainty in the $\nu_\tau$ cross section measurement. The project aims at reducing the systematic uncertainty from about 50% to 10% by measuring the $D_s$ differential production cross section. For this purpose, emulsion detectors with a nanometre-precision readout will be used to detect small kinks of the $D_s \rightarrow \tau$ decay. An emulsion detector has a position resolution of 50 nm, allowing for the detection of $D_s \rightarrow \tau \rightarrow X$ double kinks in a few mm range. Results from the beam tests in 2016-2017 will be presented together with a prospect for a pilot run in 2018 and a physics run in 2021.
