Measurements of R(D^(*)) and other missing energy B decays at the Belle II experiment

The Belle II experiment at the SuperKEKB collider is a major upgrade of the KEK "B factory" facility in Tsukuba, Japan. The accelerator has already successfully completed the first phase of commissioning in 2016 and first electron positron collisions in Belle II have taken place in April 2018. The design luminosity of SuperKEKB is 8×10³⁵ cm⁻²s⁻¹ and the Belle II experiment is expected to accumulate a data sample of about 50 ab⁻¹, a factor of 50 more than the Belle experiment. With this amount of data, decays sensitive to physics beyond the Standard Model can be studied with unprecedented precision. This report discusses our prospects for studying lepton flavor non-universality with the modes B → D^(*)τν, and the prospects for other missing energy modes sensitive to physics beyond the Standard Model, such as B → τν and $B\to {K}^{(\ast )}\upsilon \bar{\upsilon }$, which provides one of the cleanest experimental probes of the favour-changing neutral current process $b\to s\upsilon \bar{\upsilon }$.