The TeV physics of strongly interacting W's and Z's

Abstract

There are two possibilities for electroweak symmetry breaking: either there is a scalar particle much lighter than 1 TeV or the longitudinal components of W and Z bosons interact strongly at center of mass energies of order 1 TeV or more. We study the general signatures of a strongly interacting W, Z system and conclude that these two possibilities can be unambiguously distinguished by a hadron collider facility capable of observing the enhanced production of WW, W Z and Z Z pairs that will occur if W's and Z's have strong interactions. Detection of the enhanced signal over background requires hadron collisions at a center of mass energy of order .;s = 40 TeV and an integrated luminosity of order 10· 0 cm-2 • With these parameters we predict 3800 to 6000 gauge boson pairs satisfying cuts for which only 2600 pairs would be produced in the absence of strong interactions.As our results draw on the global chiral SU(2) symmetry of the scalar sector of the standard SU(2) X U(1) model, we give an extended proof, to all orders in the generalized renormalizable gauge, that high energy amplitudes of longitudinal W's and Z's are well approximated by amplitudes of the corresponding unphysical scalars. The results are applicable to the broad class of strong interaction models that admit a global chiral SU(2) symmetry.2

PYTHIA 6.4 physics and manual

“…Since the program does not contain W L or Z L distributions inside hadrons, the basic hard scattering has to be convoluted with the q → q ′ W L and q → qZ L branchings, to yield effective 2 → 3 and 2 → 4 processes. However, it is possible to integrate out the scattering angles of the quarks analytically, as well as one energy-sharing variable [Cha85]. Only after an event has been accepted are these other kinematical variables selected.…”

One-loop calculations in quantum field theory: From Feynman diagrams to unitarity cuts

“…We label those scalars as ϕ ± . If physical justification is needed, the massless scalars can be thought of as longitudinal modes of Wbosons; treating longitudinal W -bosons as massless scalar particles in Higgs boson decays is justified by the Equivalence Theorem [115,116] in the limit m H ≫ m W . We will denote the coupling of the massless scalars to the Higgs boson as g H , so that the Hϕ 2 vertex is −ig H .…”

On the Trail of the Higgs Boson

“…Chanowitz and Galliard have given a careful statement and proof of this theorem, valid for any number of vector bosons [20]. A surprising consequence of the GBET is seen in top quark decay.…”