Conformal technicolor
Abstract
We point out that the flavor problem in theories with dynamical electroweak symmetry breaking can be effectively decoupled if the physics above the TeV scale is strongly conformal, and the electroweak order parameter has a scaling dimension d = 1+epsilon with epsilon simeq 1/few. There are many restrictions on small values of epsilon: for epsilon << 1, electroweak symmetry breaking requires a finetuning similar to that of the standard model; largeN conformal field theories (including those obtained from the AdS/CFT correspondence) require finetuning for d < 2; `walking technicolor' theories cannot have d < 2, according to gap equation analyses. However, strong smallN conformal field theories with epsilon simeq 1/few avoid all these constraints, and can give rise to natural dynamical electroweak symmetry breaking with a top quark flavor scale of order 10^{1/epsilon}TeV, large enough to decouple flavor. SmallN theories also have an acceptably small PeskinTakeuchi S parameter. This class of theories provides a new direction for dynamical electroweak symmetry breaking without problems from flavor or electroweak precision tests. A possible signal for these theories is a prominent scalar resonance below the TeV scale with couplings similar to a heavy standard model Higgs.
 Publication:

Journal of High Energy Physics
 Pub Date:
 September 2006
 DOI:
 10.1088/11266708/2006/09/070
 arXiv:
 arXiv:hepph/0409274
 Bibcode:
 2006JHEP...09..070L
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 26 pages + References. Slight wording changes. Version appearing in JHEP