相关论文: Flavour-changing top quark decays in the alternati…
Flavor Changing Neutral Current decays of the top quark within the strict context of the Standard Model are known to be extremely rare. In fact, they are hopelessly undetectable at the Tevatron, LHC and LC in any of their scheduled…
Flavor changing neutral current (FCNC) interactions for a top quark $t$ decays into $Xq$ with $X$ represents a neutral gauge or Higgs boson, and $q$ a up- or charm-quark are highly suppressed in the Standard Model (SM) due to the…
We compute the branching ratios for the rare top quark decays t to c gamma and t to c Z mediated by effective flavor changing neutral couplings at the next-to-leading order in QCD including the effects due to operator mixing. After…
A search for flavour-changing neutral-current decays of a top quark into an up-type quark (either up or charm) and a light scalar particle $X$ decaying into a bottom anti-bottom quark pair is presented. The search focuses on top-quark pair…
We demonstrate that flavour-changing neutral currents in the top sector, mediated by leptophilic scalars at the electroweak scale, can easily arise in scenarios of new physics, and in particular in composite Higgs models. We moreover show…
The ATLAS and CMS experiments at the LHC have reported the observation of a possible excess of events corresponding to a new particle $h$ with mass $\sim 125$ GeV that might be the long-sought Higgs boson, or something else. Decyphering the…
A search for the flavour-changing neutral-current decay $t\to qZ$ is presented. Data collected by the ATLAS detector during 2012 from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s}=8$ TeV,…
We investigate the prospects for discovering a top quark decaying into one light Higgs boson along with a charm quark in top quark pair production at the CERN Large Hadron Collider (LHC). A general two Higgs doublet model is adopted to…
Top flavour-changing neutral interactions with a light quark q=u,c and a gauge or Higgs boson are very suppressed within the Standard Model (SM), but can reach observable levels in many of its extensions. We review the possible size of the…
The flavor changing neutral current decays $t\to c X$ ($X=\gamma,\,g,\, Z,\, H$) and $t\to c\bar \ell\ell $ ($\ell=\mu,\,\tau$) are studied in a renormalizable scalar leptoquark (LQ) model with no proton decay, where a scalar $SU(2)$…
We determine the constraints on the anomalous top-quark coupling associated with the flavor-changing neutral current vertex $\bar t c \gamma $ from the limits on the $b$-quark rare decay $b\rightarrow s \gamma$ and non-standard top-quark…
Possible non-standard tuZ and tcZ interactions, which induce flavor-changing neutral-current decays of the top quark, are studied in the effective-Lagrangian framework. The corresponding Lagrangian consists of four kinds of non-standard…
A search for flavour-changing neutral-current processes in top-quark decays is presented. Data collected with the ATLAS detector from proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s}=13$ TeV,…
The results of a search for flavor changing neutral currents in top quark decays t to Zq in events with a topology compatible with the decay chain t t-bar to Wb + Zq to ell nu b + ell ell q are presented. The search is performed with a data…
Flavor changing effects on the processes \tch, \eebs, \eebsh and \ppbs in the LHT model are investigated in this paper. We calculate the one-loop level contributions from the T-parity odd mirror quarks and gauge bosons. The results show…
In the present study, we investigate the decays of the top quark $t\rightarrow c\gamma$, $t\rightarrow cg$, $t\rightarrow cZ$ and $t\rightarrow ch$. They are extremely rare processes in the Standard Model (SM). As the $U(1)$ extension of…
ATLAS results are presented on a search for flavor-changing neutral currents (FCNC) in top quark decays at the LHC. Events are searched for where a pair of top quarks is produced and one decays through the Standard Model $t \rightarrow Wb$…
The sensitivity of ATLAS experiment to the top-quark rare decay via flavor- changing neutral currents t \to Zq (q represents c and u quarks) have been studied at \sqrt{s}= 14 TeV in two decay modes: 1. The pure leptonic decay of gauge…
Rare flavour changing neutral current (FCNC) decays of top, beauty and charm quarks can provide a powerful probe for as yet unobserved particles. Recent results on FCNC $b \to s$, $c \to u$ and $t$ transitions from the LHC experiments are…
We report a search for the flavor changing neutral current (FCNC) decay of the top quark \tZq ($q=u,c$) in \ppbar collisions at $\sqrt{s} = 1.96\tev$ using a data sample corresponding to an integrated luminosity of 1.9\invfb collected by…