Rare top decay $t\to c\gamma$ with flavor changing neutral scalar interactions in two Higgs doublet model

Abstract

Models beyond the Standard Model with extra scalars have been highly motivated by the recent discovery of a Higgs boson. The Two Higgs Doublet Model Type III considers the most general case for the scalar potential, allowing mixing between neutral CP-even and CP-odd scalar fields. This work presents the results of the study on the $t\to c\gamma$ decay at one loop level if neutral flavor changing is generated by top-charm-Higgs coupling given by the Yukawa matrix. For instance, a value for the branching ratio $Br(t\to c\gamma )\sim 10^{-6}$ for $\tan \beta =2.5$ and general neutral Higgs mixing parameters, $1.16\le {\alpha }_1\le 1.5$, $-0.48\le {\alpha }_2\le -0.1$. The number of events for the $t\to c\gamma$ decay with an integrated luminosity of 300 $f{b}^{-1}$ is estimated as $10\lesssim N_{Eff}\lesssim 100$ for the parameters of the model constrained by experimental data.

Comments: 12 pages, 12 figures