Top-antitop production from W_(L)^(+)W_(L)^(-) and Z_(L)_Z(L) scattering under a strongly interacting symmetry-breaking sector

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 W^(+)W^(−) → tṫ, Z Z → tṫ and hh → tṫ (in the regime M^(2)_(t)/v^(2) « √sM_(t)/v^(2) « s/v^(2) and to NLO in the effecti...

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Detalles Bibliográficos
Autores: Castillo, Andrés, Delgado López, Rafael, Dobado González, Antonio, Llanes Estrada, Felipe José
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/18028
Acceso en línea:https://hdl.handle.net/20.500.14352/18028
Access Level:acceso abierto
Palabra clave:53
Chiral perturbartion-theory
Higgs-boson
Electroweak parameters
Technicolor theories
Equivalence theorem
Standard model
Atlas detector
PP collisions
Pi-Pi
Lagrangians.
Física-Modelos matemáticos
Descripción
Sumario: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 W^(+)W^(−) → tṫ, Z Z → tṫ and hh → tṫ (in the regime M^(2)_(t)/v^(2) « √sM_(t)/v^(2) « s/v^(2) 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 M_(t) /v 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 tṫ production that may be enhanced by a possible strongly interacting electroweak symmetry breaking sector.