548 research outputs found
2HDM without FCNC: off the beaten tracks
We propose an alternative method of constructing two Higgs-doublet models
free from scalar mediated FCNC couplings at the tree-level. In a toy scenario,
we have presented semi realistic textures for the Yukawa matrices, which can
reproduce the approximate flavor structure in the quark sector. Presence of
flavor diagonal but nonuniversal Yukawa couplings emerges as a distinguishing
feature of such models.Comment: 8 pages, no figures, minor clarifications added, version accepted for
publication in EPJ
Cornering variants of Georgi-Machacek model using Higgs precision data
We show that in the absence of trilinear terms in the scalar potential of
Georgi-Machacek model, heavy charged scalars do not necessarily decouple from
the decay amplitude. In such scenarios, measurement of
the Higgs to diphoton signal strength can place stringent constraints in the
parameter space. Using the projected precisions at the High Luminosity LHC
(HL-LHC) and the ILC, we find that the upper bound on the triplet vacuum
expectation value can be as low as 10 GeV. We also found that when combined
with the theoretical constraints from perturbative unitarity and stability,
such variants may be ruled out altogether.Comment: 9 pages, 4 captioned figures. Accepted for publication in Phys. Rev.
Nondecoupling of charged scalars in Higgs decay to two photons and symmetries of the scalar potential
A large class of two- and three-Higgs-doublet models with discrete symmetries
has been employed in the literature to address various aspects of flavor
physics. We analyse how the precision measurement of the Higgs to diphoton
signal strength would severely constrain these scenarios due to the
nondecoupling behavior of the charged scalars, to the extent that the number of
additional scalar doublets can be constrained no matter how heavy the
nonstandard scalars are. We demonstrate that if the scalar potential is endowed
with appropriate global continuous symmetries together with soft breaking
parameters, decoupling can be achieved thanks to the unitarity constraints on
the mass-square differences of the heavy scalars.Comment: 9 pages, 2 figures, several clarifying remarks and references added,
to appear in Phys Rev
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