000001650 001__ 1650
000001650 005__ 20190829100032.0
000001650 037__ $$aBELLE2-TALK-CONF-2019-118
000001650 041__ $$aeng
000001650 088__ $$aBELLE2-TALK-DRAFT-2019-114
000001650 100__ $$aVladimir Chekelian
000001650 245__ $$aFirst look at the time-dependent CP violation using early Belle II data
000001650 260__ $$a19th Lomonosov Conference on Elementary Particle Physics$$c2019-08-24
000001650 300__ $$amult. p
000001650 500__ $$a20 min
000001650 520__ $$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. In 2018 the machine has completed a commissioning run, achieved a peak luminosity of $5.5\times 10^{33}$ cm$^{-2}$s$^{-1}$. Main operation of SuperKEKB has started in March 2019. In this presentation we report on a first look at the time-dependent CP violation using this early data set. One neutral $B$ meson is reconstructed in the $J/\psi K^0_S$ $CP$-eigenstate decay channel and the flavor of the accompanying $B$ meson is identified to be either $B^0$ or $\bar B^0$ from its decay products. We present a new concept for the time-dependent $CP$ violation fit together with initial results for the parameters of $B^0$ mixing-induced phenomena and the lifetime of $B^0$.
000001650 6531_ $$aCP violation
000001650 6531_ $$aTD CPV
000001650 6531_ $$amixing 
000001650 8560_ $$fdoris.yangsoo.kim@desy.de
000001650 8564_ $$uhttps://docs.belle2.org/record/1650/files/BELLE2-TALK-CONF-2019-118.pdf