Measurements of charmless B decays related to alpha at BaBar

TL;DR

This paper presents recent measurements of the CKM angle alpha through charmless B decays, including new decay observations and improved constraints, enhancing understanding of CP violation in B meson systems.

Contribution

It introduces new measurements of B decay modes related to alpha, including the first observation of B -> a_1(1260)+ a_1(1260)-, and refines alpha constraints using various decay channels.

Findings

Improved constraints on alpha from B+ -> rho+ rho0 decays.

First observation of B -> a_1(1260)+ a_1(1260)- decay.

Preliminary results on B decays to K_1(1270) pi and K_1(1400) pi.

Abstract

We report recent measurements of the CKM angle alpha using data collected by the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. In addition to improved constraints on alpha from the decays B+ -> rho+ rho0, we also present preliminary results of neutral and charged B meson decays to K_1(1270) pi and K_1(1400) pi and its impact on the estimate for the CKM angle alpha based on time-dependent analysis of CP-violating asymmetries in B0 -> a_1(1260) pi. Moreover we report the first observation of the decay B -> a_1(1260)+ a_1(1260)-; this mode can be used, in principle, to provide an indipendent measurement of alpha.