Manifestation of a singlet heavy up-type quark in the branching ratios of rare decays K to \pi \nu \bar{\nu}, B to \pi \nu \bar{\nu} and B to K \nu \bar{\nu}

Abstract

We investigate the implications of the model with a SU(2)-singlet up-type quark, heavy enough not to be produced at the LHC, namely, the contribution of the new quark to the branching ratios of the K to \pi \nu \bar{\nu}, B to \pi \nu \bar{\nu} and B to K \nu \bar{\nu} decays. We show that the deviation from the Standard Model can be up to 10% in the case of a 5 TeV quark. Precise measurements of these branching ratios at the future experiments will allow to observe the contributions of the new quark or to impose stronger constraints on its mass.

Comments: 13 pages, 3 figures. Submitted to the JETP Letters. A reference added, minor typos corrected