Related papers: Probing Quark-Lepton Unification with Leptoquark a…
In this paper we discuss decays of the Higgs boson to quarkonia in association with a photon. We identify a new mechanism for producing such final states in Higgs decays that leads to predictions for the decay rates that differ by an order…
New vectorlike fermions that mix with the third generation can significantly affect the tau and b Yukawa couplings. Consistent with precision electroweak measurements, the width of the Higgs boson to tau tau, b b can be reduced by O(1) with…
The production of lepton pairs in the Higgs boson decay $h \to \ell^+ \ell^- \gamma$ is studied. The emphasis is put on the structure of the Higgs boson interaction with the fermions. This interaction is chosen as a mixture of the scalar…
We propose a new observable designed to probe CP-violating coupling of the Higgs boson to W bosons using associated Higgs production. We define an asymmetry that measures the number of leptons from W decays relative to the plane defined by…
We study the Higgs boson decays and production via gluon fusion at the LHC as a probe of two typical littlest Higgs models which introduce a top quark partner with different (even and odd) T-parity to cancel the Higgs mass quadratic…
Multi-TeV e+e- collisions provide with a large enough sample of Higgs bosons to enable measurements of its suppressed decays. Results of a detailed study of the determination of the muon Yukawa coupling at 3 TeV, based on full detector…
This report summarizes latest ATLAS and CMS results on Higgs boson couplings to fermions.~Presented topics include decays into final states of pairs of tau leptons and pairs of bottom quarks as well as results on the ttH production…
A search is presented for decays beyond the standard model of the 125 GeV Higgs bosons to a pair of light bosons, based on models with extended scalar sectors. Light boson masses between 5 and 62.5 GeV are probed in final states containing…
Leptoquarks with mass in the region of $550-650$ GeV are a possible candidate for the recent excess seen by CMS in the $eejj$ and $e \nu jj$ channels. We discuss models where leptoquarks decay primarily to dark matter and jets, thereby…
We discuss possibilities to measure the tt-gamma and ttZ couplings at hadron and lepton colliders. We also briefly describe how these measurements can be used to constrain the parameter space of models of new physics, in particular Little…
We present a model for third-family quark-lepton unification at the TeV scale featuring a composite Higgs sector. The model is based on a variant of the Pati-Salam model, the so-called 4321 model, consisting of the gauge group $SU(4)\times…
The rare t-quark decays $t \to c l_j^{+} l_k^{-}$, $t \to c \tilde{\nu_j} \nu_k$ via the scalar leptoquark doublets are investigated in the minimal four color symmetry model with the Higgs mechanism of the quark-lepton mass splitting. The…
We consider the flavor-changing decays of the Higgs boson in a grand unified theory framework which is based on the SU(5) gauge group and implements the principle of minimal flavor violation. This allows us to explore the possibility of…
We discuss the Higgs boson mass sum rules in the Minimal Supersymmetric Standard Model in order to estimate the upper limits on the masses of stop quarks as well as the lower bounds on the masses of the scalar Higgs boson states. The…
Testing the Yukawa couplings of the Higgs boson to quarks and leptons is important to understand the origin of fermion masses. These proceedings will review several measurements of Higgs boson decays to two bottom quarks or two tau leptons,…
We propose a model in which the Yukawa couplings of Higgs doublets are related to the couplings of the chiral fermions to a scalar leptoquark triplet. This is due to their common origin via mixing with a vector-like family distinguished by…
We construct a model of quark-lepton unification at the TeV scale based on an $SU(4)$ gauge symmetry, while still having acceptable neutrino masses and enough suppression in flavor changing neutral currents. An approximate $U(2)$ flavor…
We propose that quarks and leptons are interchangeable entities in the high-energy limit. This naturally results in the extension of [SU(3)]^3 trinification to [SU(3)]^4 quartification. In addition to the unbroken color SU(3)_q of quarks,…
In the MSSM, the Higgs couplings to down-type quarks and leptons, normalized with respect to their corresponding Standard Model values, coincide at tree-level and this degeneracy is only slightly broken at the quantum level. Motivated by…
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the {\bf Standard Model} can develop a non-standard minimum for values of the field much larger than the weak scale. In those cases the standard…