[SEMINARI]: Johannes Hirn, 26 Oct at 12:00

[German Rodrigo Garcia]

The fate of irrelevant operators in Higgs-less effective theories

Johannes HIRN (IFIC,Valencia)

Seminari del IFIC
Tuesday 26 of October of 2004 at 12:00 PM

Resum

When constructed with Standard Model fields, the effective operators that 
generate lepton-number violation, non-universal fermion-vector couplings 
and contributions to the $S$ and $T$ parameters, are \it{irrelevant}. This 
is not the case in the absence of a light Higgs boson: in the low-energy 
effective theory for Higgs-less electroweak symmetry breaking (defined as 
a momentum expansion with order-by-order renormalization), the 
corresponding operators appear at the leading (chiral) order. To take into 
account the experimentally observed suppression of the incriminated terms, 
we propose a consistent expansion in which they are relegated to higher 
orders.