Dynamical electroweak symmetry breaking

Abstract

We review the status of and recent developments in dynamical electroweak symmetry breaking, concentrating on the ideas of technicolour and top quark condensates. The emphasis is on the essential physical ideas and experimental implications rather than on detailed mathematical formalism. After a general overview of the subject, we give a first introduction to technicolour, and extended technicolour, illustrating the ideas with a simple (unrealistic) model. Then we review the progress that has been made with enhancing the technicolour condensate, using the Schwinger-Dyson gap equation. The discussion includes the so-called walking technicolour and strong extended technicolour approaches. We then turn to the experimental prospects of technicolour models, including longitudinal gauge boson scattering experiments at the LHC, the detection of pseudo-Goldstone bosons and the hints about electroweak symmetry breaking which comes from precision measurements at LEP. We also discuss a low-scale technicolour model, which has experimental signatures at LEP and the Tevatron. Finally we turn to the idea of the top quark condensate. After reviewing the basic ideas of this approach, we turn to some extensions of these ideas involving the idea of fourth family condensates, and the role of irrelevant operators.

ASPECTS OF 3He AND THE STANDARD ELECTROWEAK MODEL

“…So while there are similarities on this Level 2 of analogies, there are some differences too which one must bear in mind. 29…”

A Search for Third Generation Leptoquarks in p$\bar{p}$ Collisions at 1.8-TeV

“…The preons can combine to form scalar or vector leptoquarks. In various hybrids of technicolor [12,13,14], leptoquarks appear as scalar bound states of a technilepton and a techniquark. The coupling strength of this type of leptoquark to ordinary matter is generally proportional to mass, so the leptoquark decays preferen- The flavor-changing neutral current decay, K----7 71"-11, can be induced by leptoquarks which couple to more than one generation of quarks.…”

“…Also the indirect searches do not address the possible effects of other exotics associated with the leptoquarks, eg. the additional gauge bosons in extended technicolor theories [14].…”

“…The theories of extended technicolor (ETC) [12,13,14] contain a rich spectrum of technihadrons. In these models the color-triplet technipions ( 7rf) are scalar lepto- This resonant production mechanism will in general enhance the cross section and efficiency for detecting the leptoquark pairs.…”

Flavor changing neutral currents

“…Technicolor is the simplest new strong confining gauge force. However, technicolor models have difficulty generating fermion masses without generating large flavor-changing neutral currents beyond what is seen empirically [37].…”