Related papers: Finite Width Effects in Top Quark Decays
The decay $A\to ZH$ is a characteristic signal of two-Higgs-doublet models (2HDMs), where $A$ and $H$ lie primarily within the same $SU(2)_L$ multiplet, leading to a coupling of order $g_2$ to the $Z$ boson. The subsequent decay $H\to…
We present a new measurement of the top quark mass in $t\bar t$ events in which both $W$ bosons from top quarks decay into lepton ($e \nu,\mu \nu$). We use events collected by the CDF experiment from $p\bar p$ collisions at \sqrt s=1.8 TeV…
Recent measurements of top-quark properties at the Tevatron are presented. CDF uses data corresponding up to 9.0 fb^{-1} to measure the ratio R of the branching fractions B(t \rightarrow Wb) / B(t \rightarrow Wq), the branching fraction for…
An importance of the detailed studies of the theoretical QCD predictions for the decay width of Standard Model Higgs boson into bottom quarks, in the case when $\rm{M_H\leq 2M_W}$, is emphasized. The effects of higher order perturbative QCD…
A search is reported for massive resonances decaying into a quark and a vector boson (W or Z), or two vector bosons (WW, WZ, or ZZ). The analysis is performed on an inclusive sample of multijet events corresponding to an integrated…
We present the first direct experimental bound on the total decay width of the top quark using 955pb^-1 of the Tevatron's ppbar collisions recorded by the Collider Detector at Fermilab. We identify 253 top-antitop pair candidate events. The…
In this note we study the prospect of high-precision measurements of W boson mass, top quark mass, and forward-backward asymmetry in Z->ee decays and the search for the Higgs boson during Run 2 to challenge the standard model.
The flavour changing decays of the top quark are severely suppressed in the Standard Model by virtue of the Glashow-Iliopoulos-Maiani mechanism. Many beyond Standard Model extensions predict the decay rates at a level that is observable in…
In this talk electroweak corrections related to the finite top quark lifetime to the total top pair threshold e+e- cross section at NNLL order are discussed. We include the absorptive parts in electroweak matching conditions of the NRQCD…
The latest results on top quark physics, namely single top quark production cross sections, $W$-boson helicity and asymmetry measurements are used to probe the Lorentz structure of the $Wtb$ vertex. The increase of sensitivity to new…
Searches for Z' bosons are most sensitive in the dilepton channels at hadron colliders. Whilst finite width and interference effects do affect the modifications the presence of BSM physics makes to Standard Model (SM) contributions, generic…
We present an update of the global fit of the Standard Model electroweak sector to latest experimental results. We include new kinematic top quark and $W$ boson mass measurements from the LHC, a $\sin^2\theta^{\ell}_{\mathrm{eff}}$ result…
In this paper, we analyze the top-quark decay $t\to Wb$ up to next-to-next-to-next-to-leading order (N$^{3}$LO) QCD corrections. For the purpose, we first adopt the principle of maximum conformality (PMC) to deal with the initial pQCD…
Top-quark decays are sensitive probes of light charged Higgs bosons ($H^\pm$) due to the sizable $t\bar t$ production cross section at the LHC in conjunction with their distinct experimental signatures. While dedicated ATLAS and CMS…
We study the finite quark mass effects of the low-energy QCD using the improved ladder Schwinger-Dyson and Bethe-Salpeter equations which are derived in the manner consistent with the vector and axial-vector Ward-Takahashi identities. The…
Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_H< 2M_W, are briefly reviewed. The effects of higher order perturbative QCD (up to alpha_s^4-level) and QED…
A search for new resonances decaying to WW, ZZ, or WZ is presented. Final states are considered in which one of the vector bosons decays leptonically and the other hadronically. Results are based on data corresponding to an integrated…
The method of the top quark mass measurement from $M_{b l}$ distribution in $t \to b l \nu$ decays can be considerably improved if applying the technique of moments and proceeding to moments of high degree. At the LHC this allows one to…
For top quark decays into heavy quark mesons $\Upsilon$ and $\bar{B}_c^*$ , a complete calculation to the leading order both in QCD coupling constant $\alpha_s$ and in $v$, the typical velocity of the heavy quarks inside the mesons, is…
In the standard model, for the t --> W b decay mode, the relative phase is 0-degrees between the dominant A(0,-1/2) and A(-1, -1/2) helicity amplitudes. However, in the case of an additional large t_R --> b_L chiral weak-transition moment,…