Abstract
We perform a complete one-loop computation of the two-body flavour-changing top decays t → ch and t → cV (V = γ, Z), within the aligned two-Higgs-doublet model. We evaluate the impact of the model parameters on the associated branching ratios, taking into account constraints from flavour data and measurements of the Higgs properties. Assuming that the 125 GeV Higgs corresponds to the lightest CP-even scalar of the CP-conserving aligned two-Higgs-doublet model, we find that the rates for such flavour-changing top decays lie below the expected sensitivity of the future high-luminosity phase of the LHC. Measurements of the Higgs signal strength in the di-photon channel are found to play an important role in limiting the size of the t → ch decay rate when the charged scalar of the model is light.
Highlights
We evaluate the impact of the model parameters on the associated branching ratios, taking into account constraints from flavour data and measurements of the Higgs properties
Two-Higgs-doublet model (A2HDM) assumes that the two Yukawa matrices coupled to the same type of right-handed fermion are aligned in flavour space, so that no FCNCs appear at tree level
A significant enhancement can be achieved in alternative scenarios of EWSB, making these processes a suitable place to look for new physics beyond the SM
Summary
The 2HDM extends the SM scalar sector with an additional complex scalar doublet. In the Higgs basis, where only one doublet acquires vacuum expectation value, the scalar fields are parametrized by [21]. G0,± correspond to the would-be Goldstone bosons, giving mass to the gauge vector bosons, while H± is a charged Higgs. Contains three neutral Higgs bosons φ0j (x) = {h(x), H(x), A(x)}, given by φ0j = RjkSk, where R is an orthogonal matrix obtained after diagonalizing the mass terms in the scalar potential [21]. In general none of the neutral Higgs bosons are CP eigenstates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
