Related papers: The t->WZb decay in the Standard Model: A Critical…
Motivated by evidence that the top quark mass lies near the $bWZ$ threshold, we compute the decay rate for $t\rightarrow bWZ$ in the Standard Model, including the effects of the finite widths of the $W$ and $Z$ bosons. In the limit where…
We present a new calculation of the t->cH decay rate in the standard model. We find that the corresponding branching fraction is B(t->cH) \sim 10^{-13} - 10^{-14} for M_Z < m_H < 2 M_W, that is about 6 orders of magnitude less than…
The t->cH decay width has been computed in the standard model with a light Higgs boson. The corresponding branching fraction has been found to be in the range B(t->cH) ~ 10^{-13} - 10^{-14} for M_Z < m_H < 2 M_W. Our results correct the…
The nonzero widths of heavy particles become significant when they appear in the final state of any decay occurring just around its kinematical threshold. To take into account such effects, a procedure, called the convolution method, was…
We discuss possible non-standard contributions to the top-quark width, particularly the virtual effects on the standard decay $t\rightarrow W^+\,b$ within the context of the MSSM. We also place a renewed emphasis on the unconventional mode…
We compute the $O(\beta_0 \alpha_s^2)$ QCD corrections to the Standard Model decay $t\rightarrow W^+ b$ as well as the non standard decay $t\rightarrow H^+ b$. We then use our results to compute the BLM scale for these decays, and study the…
The large value of the top quark mass implies that the rare top decays $t \rightarrow b W^+ Z, s W^+ Z$ and $d W^+ Z$, and $t \rightarrow c W^+ W^-$ and $u W^+ W^-$, are kinematically allowed decays so long as $m_t \ge m_W + m_Z + m_{d_i}…
In the standard model, the top quark decay width \Gamma_t is computed from the exclusive t -> bW decay. We argue in favor of using the three body decays t-> bf_i\bar{f}_j to compute \Gamma_t as a sum over these exclusive modes. As dictated…
We calculate decays of a Standard Model Higgs boson to a virtual massive particle and discuss how this depends on the massive particle total width. If the partial width of Higgs to a virtual massive particle can be measured this gives a…
In light of the discovery of a Standard Model (SM)-like Higgs boson ($h$) at the LHC, we investigate the top quark to Higgs boson transition $t\rightarrow W^{*}bh$, which is the leading $t\to h$ decay mode in the SM. We find the decay…
In these proceedings we explore the possibility of new physics manifesting itself in rare top quark decays. In particular, we adopt an effective theory description of FCNC t -> q V top quark decays and possible deviations from the SM form…
The apparent excess of $Z \rightarrow b \bar b$ events at LEP may be an indication of new physics beyond the standard model. However, in either the two-Higgs-doublet model or the minimal supersymmetric standard model, any explanation would…
The search for new physics in top quark decays at the LHC is reviewed in this paper. Results from ATLAS and CMS experiments on top quark decays within the Standard Model are presented together with the measurements of the W boson…
The polarization of the $W$ boson in $t \to W b$ decay is unambiguously predicted by the Standard Model of weak interactions and is a powerful test of our understanding of the $tbW$ vertex. The subsequent $W \to l \nu$ decay serves as a…
We study the top quark decay to b quark and W boson in the NonCommutative Standard Model (NCSM). The lowest contribution to the decay comes from the terms quadratic in the matrix describing the noncommutative (NC) effects while the linear…
We present the complete calculation of the top-quark decay width at next-to-next-to-leading order in QCD, including next-to-leading electroweak corrections as well as finite bottom quark mass and $W$ boson width effects. In particular, we…
Production cross sections for t\bar{t} and t\bar{t}j events at hadron colliders are calculated, including finite width effects and off resonance contributions for the entire decay chain, t --> bW --> b\ell\nu, for both top quarks. Resulting…
Observing a heavy charged Higgs boson produced in the near future at the Tevatron or at the LHC would be instant evidence of physics beyond the Standard Model. Whether such a Higgs boson would be supersymmetric or not it could only be…
A critical assessment of the available calculations of the top quark width is presented. QCD corrections, the finite mass of the $b$ quark and the effect of the $W$ width are included as well as the electroweak corrections. The relative…
The measurement of the invisible Z-boson decay width at e+e- colliders can be done "indirectly", by subtracting the Z-boson visible partial widths from the Z-boson total width, or "directly", from the process e+e- -> \gamma \nu \bar{\nu}.…