Longitudinal, transverse-plus and transverse-minus W-bosons in unpolarized top quark decays at O(alphas)
Abstract
We consider the O(alphas) radiative 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. The O(alphas) radiative corrections lower the normalized longitudinal rate GammaL/Gamma by 1.06% and increase the the normalized transverse-minus rate Gamma-/Gamma by 2.17%. We find that the normalized transverse-plus rate Gamma+/Gamma, which vanishes at the Born term level for mb->0, receives radiative correction contributions at the sub-percent level. We discuss mb!=0 effects for the Born term and the alphas-contributions but find these to be small. Our results are discussed in the light of recent measurements of the helicity content of the W in top quark decays by the CDF Collaboration.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.