# Unitarity in composite Higgs approaches with vector resonances

Abstract : We examine a simple Composite Higgs Model (CHM) with vector resonances in addition to the Standard Model (SM) fields in perturbation theory by using the $K$-matrix method to implement unitarity constraints. We find that the $W_LW_L$ scattering amplitude has an additional scalar pole (analogous to the $\sigma$ meson of QCD) as in generic strongly interacting extensions of the SM. The mass and width of this dynamically generated scalar resonance are large and the mass behaves contrary to the vector one, so that when the vector resonance is lighter, the scalar one is heavier, and vice versa. We also attempt an interpretation of this new resonance. Altogether, the presence of the vector state with the symmetries of the CHM improve the low-energy unitarity behavior also in the scalar-isoscalar channel.
Type de document :
Article dans une revue
Physical Review D, American Physical Society, 2015, 91, pp.095013. 〈10.1103/PhysRevD.91.095013〉

http://hal.in2p3.fr/in2p3-01162701
Contributeur : Dominique Girod <>
Soumis le : jeudi 11 juin 2015 - 11:16:39
Dernière modification le : jeudi 15 mars 2018 - 11:40:10

### Citation

D. Barducci, H. Cai, S. De Curtis, F. J. Llanes-Estrada, S. Moretti. Unitarity in composite Higgs approaches with vector resonances. Physical Review D, American Physical Society, 2015, 91, pp.095013. 〈10.1103/PhysRevD.91.095013〉. 〈in2p3-01162701〉

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