Results on \phi 2 from e+e- colliders

TL;DR

This paper summarizes measurements from BaBar and Belle experiments on B meson decays to constrain the CKM angle  (1) using various decay channels and CP asymmetry data.

Contribution

It provides a comprehensive update on 1 measurements from e+e- collider experiments, combining multiple decay modes and CP asymmetries for improved constraints.

Findings

Constraints on 1 from B b1 b1 b1 decays.

Measured CP asymmetries and branching fractions.

Polarization measurements in B decays.

Abstract

We present a summary of measurements sensitive to the CKM angle \phi 2 (\alpha), performed by the BaBar and the Belle experiments which both collect B\bar{B} pairs produced at the \Upsilon(4S) resonance in asymmetric e+e- collisions. We discuss the decays B -> \pi \pi, \rho\rho, a_1\pi and (\rho\pi)^0. The CP asymmetries, branching fractions and polarizations obtained are used to constrain \phi 2.