Flavor Changing Neutral Scalar Currents atμ+μ−Colliders

Abstract

The prospect of observing the flavor changing decay H → tc of a neutral Higgs boson produced via s-channel and its subsequent decay into tc is considered at a µ + µ − collider. Numerical estimates are given in the context of a two Higgs doublet model with flavor changing couplings. It is found that for many values of the model parameters such tree-level flavor changing decays will be produced at an observable level. In addition studies of the helicity of the top will allow the determination of the relative strengths of the flavor changing Higgs couplings and these may be measured with about 10 3 events.

CP violation in top physics

“…If the Higgs sector contains two or more doublets, then the Higgs couplings may be FC (Flavor Changing) [84,240] (see also section 3.2.2). This can lead to a dramatic tree-level signature of µ + µ − → tc (or ct) due to the neutral Higgs resonance [241]. At the same time FC processes do occur at the loop level in the SM and in practically all of its extensions, even if they are forbidden at the tree-level.…”

“…A Z,γ tc , B Z,γ tc are form factors which are induced at the loop level. As mentioned previously, although small in the SM, they may be generated at reasonable levels in some extensions of the SM, for instance, in multi Higgs scenarios which give H 0 → tc [240,241].…”

Flavor-changing neutral Higgs boson couplings and top-quark–charm-quark production at the Next Linear Collider

“…Turning away from e + e − linear colliders, the process µ + µ − → h, H, A → tc [18] at a possible future muon collider capitalizes on the larger Higgs-µ-µ coupling and a sharp Higgs resonance peak. However, because of the narrow width of the Higgs boson, this would demand [6] precise tunings of the muon energies to find the Higgs resonance.…”

Photonic and QCD radiative corrections to Higgs-boson production inμ+μ−→ff¯Dittmaier1, Kaiser2 2002Phys. Rev. D120150View full textAdd to dashboardCite

“…[ 13]. More information on the Higgs phenomenology at muon colliders can be found in the literature [ 9,10,11,12,13,14,15,16,17] including in particular studies of CP violation [ 14], Higgs decays into τ + τ − pairs [ 15], and flavourchanging neutral currents [ 16]. In this context, the possibility to produce polarized muon beams proved to be very useful.…”