Description
The Belle and Belle II experiment have collected a 1.2 ab$^{-1}$ sample of $e^+e^-\to B\bar{B}$ decays at a centre-of-mass energy corresponding to the $\Upsilon(4S)$ resonance. The SuperKEKB collider is asymmetric, providing a boost to the $B$ mesons in the laboratory frame, so we can perform measurements of time-dependent $C\!P$ violation. Among the new results, we measure $CP$-violating parameters related to the determination of the least well-known angle of the unitarity triangle $\alpha$ using the decay $B^0\to\rho^+\rho^-$. In addition, we present a measurement of $B^0\to K^{0}_{\rm S}\pi^+\pi^-\gamma$, which is sensitive to beyond-the-standard-model physics.
Author
Steven Robertson
(IPP / UofA)
