Technihadron Production and Decay Rates in the Technicolor Straw Man Model

We present hadron collider production rates for the lightest colorsinglet technihadrons in a simple “straw-man” model of low-scale technicolor. These rates are presented in a way to facilitate their encoding in PYTHIA. This document is a companion to my paper, “Technihadron Production and Decay in Low-Scale Technicolor”. [email protected] 1 1 The Technicolor Straw Man Model In this note we present formulas for the decay rates and production cross sections for the lightest color-singlet technivector mesons VT = ρT and ωT . The decay rates have been revised for VT → GπT , where G is a transversely polarized electroweak gauge boson, γ, Z, or W. The gauge boson polarization is defined relative to the spin direction of the technivector meson in the latter’s rest frame. This is parallel to the beam direction in a hadron or lepton collider. Some basic references are: for technicolor and extended technicolor [1, 2]; for walking technicolor [3]; for top condensate models and topcolor-assisted technicolor (TC2) [4, 5, 6, 7]; for multiscale technicolor [8]; for signatures of low-scale technicolor in hadron and lepton colliders [9]. As has been emphasized in Refs. [8, 9], a large number ND of technifermion doublets are required in TC2 models with a walking technicolor gauge coupling. In turn, ND technidoublets imply a relatively low technihadron mass scale, set by the technipion decay constant FT ≃ Fπ/ √ ND, where Fπ = 2 G −1/2 F = 246GeV. In the models of Ref. [7], for example, the number of electroweak doublets of technifermions ND ≃ 10 and FT ≃ 80GeV. To set the ground rules for our calculations, we adopt the “Technicolor Straw Man Model”. In the TCSM, we assume that we can consider in isolation the lowest-lying bound states of the lightest technifermion doublet, (TU , TD). These are assumed to be color singlets and to transform under technicolor SU(NTC) as fundamentals; they have electric charges QU and QD. The bound states in question are vector and pseudoscalar mesons. The vectors include a spin-one isotriplet ρ T and an isosinglet ωT . Since techniisospin is likely to be a good approximate symmetry, ρT and ωT should be nearly degenerate. 1 The pseudoscalars, or technipions, also comprise an isotriplet Π T and an isosinglet Π T . However, these are not mass eigenstates. In the TCSM, we assume the isovectors are simple two-state mixtures of the longitudinal weak bosons W L , Z 0 L—the true Goldstone bosons of dynamical electroweak symmetry breaking in the limit that the SU(2)⊗U(1) couplings g, g vanish— Even though ρ0T and ωT have nearly the same mass, they do not mix much because, as in QCD, they have rather different decay rates.