Résumé du preprint Irfu-09-299

Measurements of the angle alpha at B factories
G. Vasseur
The determinations of the angle alpha of the unitarity triangle at the B factories are reviewed with some emphasis on the updated measurement in the B to rho rho decay modes. When 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, a precise measurement of alpha is obtained: alpha = (89.0 +4.4 -4.2).