1207.4004 (Damir Becirevic et al.)

Impact of $B\to K^\ast_0 \ell^+\ell^-$ on the New Physics search in
$B\to K^\ast \ell^+\ell^-$ decay    [PDF]

Damir Becirevic, Andrey Tayduganov

We discuss the uncertainty related to the amount of unwanted $B\to K_0^\ast (K\pi)\ell^+\ell^-$ events in the sample of $B\to K^\ast (K\pi)\ell^+\ell^-$. 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 $B\to K^\ast (K\pi)\ell^+\ell^-$ decay. Although the transverse asymmetries should be unaffected by the presence of the $S$-wave $K\pi$ pairs, coming from the scalar $K_0^\ast$ meson, we show that in practice their normalization is sensitive to the those events and can entail a sizable uncertainty in transverse asymmetries around $q^2=2$ GeV. For other $q^2$'s that error is under about 10%.

View original: http://arxiv.org/abs/1207.4004