Charmless 2- and 3-Body B Decays and the Angle alpha(phi_2)

Abstract

We present preliminary measurements of branching fractions and CP-asymmetry parameters in two- and three-body charmless hadronic B decays. The available data sample consists of 227 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. We establish the observation of the decays B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0} and B{sup 0} {yields} K{sup 0}{bar K}{sup 0} and constrain the CKM angle {alpha} with a full SU(2) isospin analysis in the B {yields} {pi}{pi} system and with a B{sup 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0} time-dependent Dalitz plot analysis.