Use of W-boson longitudinal–transverse interference in top quark spin-correlation functions: II

Theoretical Physics


This continuation of the derivation of general beam-referenced stage-two spin-correlation functions is for the analysis of top–antitop pair-production at the Tevatron and at the Large Hadron Collider. Both the gluon-production and the quark-production contributions are included for the charged-lepton-plus-jets reaction pp or \(p\bar{p}\rightarrow t\bar{t}\rightarrow(W^+b)(W^-\bar{b})\rightarrow(l^+\nu b)(W^-\bar{b})\). There is a simple 4-angle beam-referenced spin-correlation function for determination of the relative sign of or for measurement of a possible non-trivial phase between the two dominant \(\lambda_b=-1/2\) helicity amplitudes for the \(t\rightarrow W^+b\) decay mode. There is an analogous function and tests for \(\bar{t}\rightarrow W^-\bar{b}\) decay. This signature requires use of the \((t\bar{t})_{\text{c.m.}}\) energy of the hadronically decaying W-boson, or the kinematically equivalent cosine of the polar angle of \(W^\mp\) emission in the antitop (top) decay frame. Spinors and their outer-products are constructed so that the helicity-amplitude phase convention of Jacob and Wick can be used throughout for the fixing of the signs associated with this large W-boson longitudinal–transverse interference effect.


Field Theory Quantum Field Theory Large Hadron Collider Relative Sign Interference Effect 
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© Springer-Verlag 2006

Authors and Affiliations

  1. 1.Department of PhysicsState University of New York at BinghamtonBinghamtonUSA

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