Composite Resonances effects on EWPT and Higgs diphoton decay rate

Understand

In scenarios of strongly coupled electroweak symmetry breaking, heavy composite particles of different spin and parity may arise and cause observable effects on signals that appear at loop levels.

• The recently observed process of Higgs to $\gamma \gamma$ at the LHC is one of such signals.
• We study the new constraints that are imposed on composite models from $H\to \gamma\gamma$, together with the existing constraints from the high precision electroweak tests.
• We use an effective chiral Lagrangian to describe the effective theory that contains the Standard Model spectrum and the extra composites below the electroweak scale.