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Limit on the B0->rho0rho0 Branching Fraction and Implications for the CKM Angle alpha

The BABAR Collaboration·B. Aubert et al
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Abstract

We search for the decay B0 -> rho0 rho0 in a data sample of about 227 million Upsilon(4S)-> BBbar decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We find no significant signal and set an upper limit of 1.1*10^-6 at 90% CL on the branching fraction. As a result, the uncertainty due to penguin contributions on the CKM unitarity angle alpha measured in B -> rho rho decays is 11 degrees at 68% CL.

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The BABAR Collaboration, B. Aubert et al. 2004-12-23. Limit on the B0->rho0rho0 Branching Fraction and Implications for the CKM Angle alpha. https://doi.org/10.1103/physrevlett.94.131801

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