Measurements of the angle alpha (phi2) at B factories
  The measurements of the angle alpha (phi2) of the unitarity triangle at the B factories are reviewed. The value of alpha determined by combining the results obtained in the B to pi pi, B to rho pi, and B to rho rho modes by both the BABAR and Belle experiments is (87.5 +6.2 -5.3) degrees. 
G.Vasseur