Muon Veto analysis in the first XENON1T science run.
XENON1T, located at Laboratori Nazionali del Gran Sasso, is currently the largest experiment for direct dark-matter search. It consists of a dual phase TPC filled with 2 tonnes of xenon, and has completed the first science run in January 2017, collecting 34 live days of data. In order to set the best exclusion limit, every source of background has to be minimized. The external backgrounds ($i.e.$, cosmic radiation and ambient radioactivity) are reduced with the Muon Veto system, that acts both as a passive shield and an active muon veto. In this contribution I will present the Muon Veto analysis of the first XENON1T science run.