Constraining wrong-sign $hbb$ couplings with $h\to {\rm Y}\gamma$

Abstract

The rare decay $h\to {\rm Y}\gamma$ has a very small rate in the Standard Model, due to a strong cancellation between the direct and indirect diagrams. Models with a changed $hbb$ coupling can thus lead to a great increase in this decay. Current limits on two Higgs doublet models still allow for the possibility that the $hbb$ coupling might have a sign opposite to the Standard Model; the so-called "wrong-sign". We show how $h\to {\rm Y}\gamma$ can be used to put limits on the wrong-sign solutions.

Comments: 7 pages, 3 figures