相关论文: Three Numerical Puzzles and the Top Quark's Chiral…
This talk concerns some theoretical patterns of the helicity amplitudes for t --> W b decay. The patterns involve both the standard model's four decay helicity amplitudes, A_{SM}, and also the amplitudes A_{+} in the case of an additional…
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,…
To quantitatively assay future measurements of competing observables in t --> W b decay, we consider the g_{V-A} coupling values of the helicity decay parameters versus those for "(V-A)+ Single Additional Lorentz Structures". There are 2…
For the observed t --> W b decay, an intensity-ratio equivalence-theorem for two Lorentz-invariant couplings is shown to be related to symmetries of tWb-transformations. Three explicit tWb-transformations, A_{+}=M A_{SM}, ... relate the…
For the t --> W b decay mode, an intensity-ratio equivalence for two distinct Lorentz-invariant couplings is shown to be a consequence of symmetries of tWb-transformations. Three explicit tWb-transformations connect the four standard…
With initial and final particles on-shell, the anomalous weak-magnetic dipole moments of b and c quarks are electroweak gauge invariant quantities of the effective couplings Zb\bar{b} and Zc\bar{c}, respectively, and good candidates to test…
The standard model(SM) predicts only a $g_{V-A}$ coupling in $t \to W^+ b$ decay. However, if additional Lorentz structures exist, they can manifest themselves in high energy processes such as this via non-SM values of the helicity…
Tests of the Lorentz structure of t --> W b decay will be carried out at the Tevatron, and later at the LHC and at a NLC. To quantitatively assay future measurements of competing observables, we consider the (V-A) coupling values of the…
Measurements of several top-quark properties, obtained from the CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8 TeV are presented. The results include measurements of the top pair charge asymmetry, the W helicity…
We investigate several quantities, defined in the decays of top quark pairs, which can be used to explore non-standard Wtb interactions. Two new angular asymmetries are introduced in the leptonic decay of top (anti)quarks. Both are very…
We identify the two scalar leptoquarks capable of generating sign-dependent contributions to leptonic magnetic moments, $R_2\sim (\mathbf{3}, \mathbf{2}, 7/6)$ and $S_1\sim (\mathbf{3}, \mathbf{1}, -1/3)$, as favoured by current…
To enable an evaluation of future measurements of the helicity parameters for " t --> W b " decay in regard to " T_FS violation", this paper considers the effects of an additional pure-imaginary coupling, (i g/2 Lambda) or (i g), associated…
We measure the branching fraction of the top quark to longitudinally and right-handed polarized $W$ bosons, $F_0$ and $F_+$, using approximately 200 pb$^{-1}$ of $\bar{p}p$ collisions collected by the CDF II detector. We analyze two…
We provide a framework for the analysis of the W boson helicity in the decay of the top quark that is based on a general effective tbW coupling. Four independent coupling coefficients can be uniquely determined by the fractions of…
We review and update current limits on possible anomalous couplings of the top quark to gauge bosons. We consider data from top quark decay (as encoded in the $W$-boson helicity fractions) and single-top production (in the $t$-, $s$- and…
A search for a heavy resonance decaying to a top quark and a W boson in the fully hadronic final state is presented. The analysis is performed using data from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to…
Due to the absence of hadronization effects and the large top mass, top quark decay will be uniquely sensitive to fundamental electroweak physics at the Tevatron, at the LHC, and at a future linear collider. A complete measurement of the…
A measurement of the W boson helicity is presented, where the W boson originates from the decay of a top quark produced in pp collisions. The event selection, optimized for reconstructing a single top quark in the final state, requires…
For the " t --> W b " decay mode, an intensity-ratio equivalence-theorem for two Lorentz-invariant couplings is shown to be related to symmetries of tWb-transformations. Explicit tWb-transformations, A_{+}=M A_{SM}, P A_{SM}, B A_{SM}…
If $c$ and $t$ quarks are strongly mixed with a weak singlet charge $2/3$ quark, $BR(t\to \ell\nu + X)$ could be suppressed via the $t\to cH^0$ mode, thereby the top quark could still hide below $M_W$, whereas the heavy quark signal…