https://doi.org/10.1140/epjc/s10052-017-4991-6
Regular Article - Theoretical Physics
Top–antitop production from 
and 
scattering under a strongly interacting symmetry-breaking sector
1
Departamento de Física, Facultad de Ciencias, Universidad Nacional de Colombia, Sede Bogotá, Ciudad Universitaria, Bogotá, 111321, Colombia
2
Departamento de Física Teórica I, Universidad Complutense de Madrid, 28040, Madrid, Spain
* e-mail: rdelgadol@ucm.es
Received:
23
November
2016
Accepted:
15
June
2017
Published online:
1
July
2017
By considering a non-linear electroweak chiral Lagrangian, including the Higgs, coupled to heavy quarks, and the equivalence theorem, we compute the one-loop scattering amplitudes 
, 
and 
(in the regime 
and to NLO in the effective theory). We calculate the scalar partial-wave helicity amplitudes which allow us to check unitarity at the perturbative level in both 
and s/v. As with growing energy perturbative unitarity deteriorates, we also introduce a new unitarization method with the right analytical behavior on the complex s-plane and that can support poles on the second Riemann sheet to describe resonances in terms of the Lagrangian couplings. Thus we have achieved a consistent phenomenological description of any resonant 
production that may be enhanced by a possible strongly interacting electroweak symmetry breaking sector.
© The Author(s), 2017
