William Sutcliffe

12 July 2019
EPS-HEP2019

Abstract: The 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 8×1035 cm−2s−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 5.5×1033 cm−2s−1, and Belle II has recorded a data sample of about 0.5 fb−1. Main operation of SuperKEKB has started in March 2019. In this presentation we show first results from studying missing energy signatures, such as leptonic and semileptonic B meson decays based on early Belle II data. We report first studies on re-measuring important standard candle processes, such as the abundant inclusive B→Xℓν and B→D∗ℓν decays. Furthermore, we will also present an overview of the semileptonic B decays that will be measured in the upcoming years at Belle II and discuss prospects for important B-anomalies like R(D) and R(D*), as well as other tests of lepton flavor universality. Early physics goals of the Belle II physics program are also to rediscover rare B decays. Especially radiative b→sγ decays can be measured on a small dataset and in the near future Belle II can provide independent tests of anomalies in b→sℓℓ decays. Ultimately, the clean Belle II environment will allow to study modes with large missing energy such as B→K∗νν¯.

Note: 20 min