Using t→bb̄c to search for new physics

We consider new-physics (NP) contributions to the decay t→bb̄c. We parametrize the NP couplings by an effective Lagrangian consisting of 10 Lorentz structures. We show that the presence of NP can be detected through the measurement of the partial width. A partial identification of the NP can be achi...

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Autores principales: Kiers, Ken, Knighton, Tal, London, David, Russell, Matthew, Szynkman, Alejandro Andrés, Webster, Kari
Formato: Articulo
Lenguaje:Inglés
Publicado: 2011
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/84731
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Sumario:We consider new-physics (NP) contributions to the decay t→bb̄c. We parametrize the NP couplings by an effective Lagrangian consisting of 10 Lorentz structures. We show that the presence of NP can be detected through the measurement of the partial width. A partial identification of the NP can be achieved through the measurements of a forward-backward-like asymmetry, a top-quark-spin-dependent asymmetry, the partial-rate asymmetry, and a triple-product asymmetry. These observables, which vanish in the standard model, can all take values in the 10%-20% range in the presence of NP. Since |V tbVcb|VtsVcs|, most of our results also hold, with small changes, for t→ss̄c.