Dark sector physics at the Belle II experiment

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 x 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 x 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. Already this early data set with specifically designed triggers offers the possibility to search for a large variety of dark sector particles in the GeV mass range complementary to the Large Hadron Collider (LHC) and dedicated low energy experiments; these searches will benefit from more data in the process of being accumulated. This talk will review the state of the dark sector searches at Belle II with a focus on the discovery potential of the early data, and show the first results.