000001481 001__ 1481
000001481 005__ 20190616153651.0
000001481 037__ $$aBELLE2-CONF-PROC-2019-004
000001481 041__ $$aeng
000001481 100__ $$aJakub Kandra
000001481 245__ $$aB lifetime and $B^0-\bar B^0$ mixing results from early Belle II data
000001481 260__ $$a$$c2019-06-17
000001481 300__ $$a7
000001481 520__ $$aThe Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. From February to July 2018, the machine has completed a commissioning run, achieved a peak luminosity of $5.5\times 10^{33}$ cm$^{-2}$s$^{-1}$, and Belle II has recorded a data sample of about 0.5 fb$^{-1}$. Main operation of SuperKEKB has started in March 2019. We use this dataset to characterize the performance of the detector regarding the tracking of charged particles, the reconstruction of known resonances, and the capability of identifying displaced decay vertices. To assess the B Physics capabilities of the experiment, one of the first benchmarks consists in the measurement of the lifetime of B mesons and of the $B^0-\bar B^0$ mixing frequency. We present the first results, based on samples of B mesons that decay to hadronic and semileptonic final states.
000001481 6531_ $$avertex detector
000001481 6531_ $$aalignment
000001481 6531_ $$aweak modes
000001481 6531_ $$aB lifetime
000001481 6531_ $$aB-Bbar mixing
000001481 700__ $$aAlessandro Gaz
000001481 8560_ $$fjakub.kandra@desy.de