Impact of B → K0*l+l- on the New Physics search in B → K*l+l- decay

We discuss the uncertainty related to the amount of unwanted B -> K-0*(K pi)l(+)l(-) events in the sample of B -> K*(K pi)l(+)l(-) ones. Those events can increase the measured differential decay rate by up to 10% in the low q(2) region, and can be a source of non-negligible uncertainty in the full angular distribution of the B -> K*(K pi)l(+)l(-) decay. Although the transverse asymmetries should be unaffected by the presence of the S-wave K pi pairs, coming from the scalar K-0* meson, we show that in practice, their normalization might be sensitive to those events and could entail a sizable uncertainty in transverse asymmetries around q(2) = 2 GeV2. For other q(2)'s that error is under 10%. (C) 2012 Elsevier B.V. All rights reserved.