On $B\to K^{(\ast )}\bar{\nu }\nu$ decays in and beyond the Standard Model

Abstract

In this talk an analysis of the rare exclusive $B$ decays $B\to K\nu \bar{\nu }$ and $B\to K^{\ast }\nu \bar{\nu }$ within and beyond the Standard Model is presented. Combining new form factor determinations from lattice QCD with light-cone sum rule results and including complete two-loop electroweak corrections to the SM Wilson coefficient, precise Standard Model predictions will be given. Beyond the SM, we make use of an effective theory with dimension-six operators invariant under the SM gauge symmetries to relate NP effects in $b\to s\bar{\nu }\nu$ transitions to $b\to s{\ell }^{+}{\ell }^{-}$ transitions and use the wealth of experimental data on $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ and related modes to constrain NP effects in $B\to K^{(\ast )}\nu \bar{\nu }$. We then consider leptoquark models as a showcase for models where in principle large effects are possible.

Comments: To be published in the Proceedings of EPS-HEP in Vienna, July 2015, 7 pages, 2 figures