Electroweak and finite width corrections to top quark decays into transverse and longitudinalWbosons

Abstract

We calculate the electroweak and finite width corrections to the decay of an unpolarized top quark into a bottom quark and a W -gauge boson where the helicities of the W are specified as longitudinal, transverse-plus and transverse-minus. Together with the O(αs) corrections these corrections may become relevant for the determination of the mass of the top quark through angular decay measurements.

Azimuthal correlation between the(p→l,p→Xb)andGroote1, Huo2, Kadeer3 et al. 2007Phys. Rev. DSelf Cite

“…In [1] we determined the NLO QCD corrections to longitudinally polarized top quarks from the longitudinal part of the intermediate gauge bosons (Z and/or γ) in e + − e − -annihilation. The NLO QCD and electroweak corrections to transverse-plus W bosons in top quark decays have been calculated in [2]. The purpose of this note is to determine the NLO QCD corrections to the afore-mentioned azimuthal correlation in polarized top quark decay.…”

“…For the latter two above cases the next-to-leading-order (NLO) corrections have been computed in [1] and [2]. In [1] we determined the NLO QCD corrections to longitudinally polarized top quarks from the longitudinal part of the intermediate gauge bosons (Z and/or γ) in e + − e − -annihilation.…”

Measurement of the helicity fractions ofWbosons from top quark decays using fully reconstructedtt¯events with CDF II

“…The fraction of longitudinally polarized W bosons is defined by [3], gives F 0 = 0.697 ± 0.007, where the given uncertainty is only due to the uncertainty in the top quark mass. Next-toleading-order corrections to the total decay width and the partial decay width into longitudinal W bosons amount to about -10% [10,11,12,13,14,15,16,17,18,19]. However, the fraction of longitudinal W bosons is only negligibly changed.…”

Top and bottom tensor couplings from a color octet scalar

“…LHC related phenomenological studies for these couplings also exist, for example the study of W helicity fractions and angular asymmetries [20][21][22] as well as T-odd observables [23][24][25]. Recent overviews of anomalous couplings in the top-quark and Higgs sectors can be found in Ref.…”