Related papers: Top flavour-changing neutral interactions: theoret…
We propose a top hypercharge model with gauge symmetry SU(3)_C x SU(2)_L x U(1)_1 x U(1)_2 where the first two families of the Standard Model (SM) fermions are charged under U(1)_1 while the third family is charged under U(1)_2. The U(1)_1…
We study the anomalous production of a single top quark in association with a Higgs boson at the LHC originating from flavor changing neutral current (FCNC) interactions in $tqg$ and $tqH$ vertices. We derive the discovery potentials and…
Models of Beyond the Standard Model (BSM) physics, like the Minimal Supersymmetric Standard Model (MSSM), often involve an extended Higgs sector, giving rise to extra neutral or charged Higgs bosons. The discovery reach expected from…
We investigate the potential of the HL-LHC for discovering new physics effects via the same-sign top pair signatures. We focus on the semi leptonic (electron and muon) decay of the top quarks and study the reach for a simplified model…
Many extensions of the Standard Model contain (pseudo)scalar bosons with masses in the TeV range. At hadron colliders, such particles would predominantly be produced in gluon fusion and would decay into top quark pair final sates, a signal…
Determination of the top-quark Yukawa couplings in the process e+ e- -> t \bar{t} Z has been studied for the high luminosity option (\int L=500\fbinver) of a linear e+e- collider. Polarization of the electron beam has been considered. The…
We study low energy experimental constraints on an anomalous top-quark coupling associated with the flavor-changing neutral current vertex $Z \bar t c$. In view of these constraints, we discuss the experimental observability of the induced…
A search for flavour-changing neutral current (FCNC) processes in top-quark decays is presented. Data collected from proton-proton collisions at the LHC at a centre-of-mass energy of $\sqrt{s}=13$ TeV corresponding to an integrated…
The sensitivity of the ATLAS experiment to the top-quark rare decay via flavour-changing neutral currents t --> Hq (q represents c and u quarks) has been studied at sqrt{s} = 14 TeV in the decay mode of ttbar --> HqWb --> WW*q,Wb -->l \nu l…
We examine the decays $t\rightarrow c\gamma$ and $c Z^0$ in the Standard Model with an extra scalar doublet and no discrete symmetry preventing tree-level flavour changing neutral currents. The Yukawa couplings of the new scalars are…
Having a mass comparable to the weak scale, the top quark may have a sizable flavor changing couplings to Higgs bosons. We show that such couplings can be probed at the LHC through the parton subprocess $c(\bar c)g \to t (\bar t)A^0$, where…
We consider the wrong-Higgs interactions such as type-III two Higgs doublet models. Generally, such interactions cause flavor problems. However, if new Yukawa interactions have the same flavor structure as that of the standard model(SM), we…
In theories of Partial Compositeness the top quark is a mixture of a composite and an elementary state, and as a consequence its interactions with gauge bosons are expected to deviate from those of a point-like object. At sufficiently large…
We study various channels of top and Higgs Flavor Changing Neutral Couplings (FCNC) in the two Higgs doublet Model with natural flavor conservation (2HDM-I and 2HDM-II). We update known results about t\to c \gamma, c Z, cg and comment on…
We study the behaviour of the flavour changing neutral currents in the Left-Right Symmetric Model related to the presence of spontaneous CP phases. To do this, we explore four cases corresponding to combinations of maximal and no CP…
We discuss scenarios for BSM physics near the TeV, motivated by the hierarchy problem and the flavour puzzle, and review their experimental tests at present and future colliders. Strong LHC constraints on couplings to light quarks motivate…
The observed flavor-changing neutral-current (FCNC) processes in the standard model (SM) arise from the loop diagrams involving the weak charged currents mediated by the $W$-gauge boson. Nevertheless, the top-quark FCNCs and lepton-flavor…
Top quark interactions offer a window into possible new high scale physics and many models of new physics predict that the top quark interactions will deviate significantly from those predicted by the Standard Model (SM). We present an…
For a model with a fourth family of quarks, new sources of flavor changing neutral currents are identified by confronting the unitary 4x4 quark mixing matrix with the experimental measured values of the familiar 3x3 quark mixing matrix. By…
The claimed finding of a light Higgs boson makes the minimal Standard Model unitary. Yet we recall that the general low-energy dynamics for the minimal electroweak symmetry breaking sector with three Goldstone bosons and one light scalar is…