PT Journal
AU Pich, A
   Rosell, I
   Sanz-Cillero, JJ
TI Oblique S and T constraints on electroweak strongly-coupled models with a light Higgs
SO Journal of High Energy Physics
JI J. High Energy Phys.
PY 2014
BP 157
EP 35pp
VL 01
IS 1
DI 10.1007/JHEP01(2014)157
LA English
DE Higgs Physics; Beyond Standard Model; Chiral Lagrangians; Technicolor and Composite Models
AB Using a general effective Lagrangian implementing the chiral symmetry breaking SU(2)(L) circle times SU(2)(R) -> SU(2)(L+R), we present a one-loop calculation of the oblique S and T parameters within electroweak strongly-coupled models with a light scalar. Imposing a proper ultraviolet behaviour, we determine S and T at next-to-leading order in terms of a few resonance parameters. The constraints from the global fit to electroweak precision data force the massive vector and axial-vector states to be heavy, with masses above the TeV scale, and suggest that the W+W- and and ZZ couplings of the Higgs-like scalar should be close to the Standard Model value. Our findings are generic, since they only rely on soft requirements on the short-distance properties of the underlying strongly-coupled theory, which are widely satisfied in more specific scenarios.
ER