2022-07-01 17:16


Conference: Bucharest University Faculty of Physics 2019 Meeting

Section: Nuclear and Elementary Particles Physics

The DsTau Experiment: Study of Tau Neutrino Production

Madalina Mihaela MILOI (1,2) , Elena FIRU (1), on behalf of DsTau collaboration

1) Institute of Space Science, Romania

2) Faculty of Physics, University of Bucharest


tau neutrino, nuclear track emulsions, Ds meson

The DsTau experiment at the CERN SPS is proposing to study tau-neutrino production aiming to provide important information for future ντ measurements, where high ντ statistics is expected. First direct evidence of tau-neutrino interaction was reported by the DONUT (Direct Observation of NU Tau) Collaboration in 2000, when they measured the ντ charged-current (CC) cross section, but this was done with a systematic uncertainty larger than 50%. Therefore, one of our goals is to reduce the systematic uncertainty in the cross section evaluation to the 10% level. This can be realized by measuring the ντ production from Ds+ and Ds- decays. For this, nuclear emulsions are the most suitable devices, thanks to their high spatial and angular resolution. The difficulty of measuring ντ interactions is due to the relative rarity of the sources of ντ and difficulty to unambiguously identify the short-lived τ lepton with mean lifetime 2.9 x 10-13 s produced in ντ charged-current interactions. The nuclear emulsions are the most suitable devices, to characterize τ lepton, thanks to their best resolution. The nuclear track emulsion technique is based on relatively conservative techniques, but it still has challenging points. Now the emulsion technologies are developed with automatic scanning system and neutrino experiments will receive benefit of the capacity of nuclear emulsion to distinguish all 3 flavors of neutrinos. In 2016, a prototype test experiment was performed, in DsTAU project, with 20 m2 emulsion surface, corresponding to a scale of about 1:20 of the final setup. This test provided a proof of the principle of the double kink topology detection and an improvement of the angular resolution. The results were used to optimize the module structure for 2018 pilot run where we use 400 m2 emulsion in total and conduct at recording 10% of the experimental data.


Prof. Oana Ristea (from Faculty of Physics) and prof. Titi Preda (from Institute of Space Science), for sharing their knowledge and the patience in answering to all my questions.