Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at √s = 13 TeV

• Autor(a) principal: Tonon, N.
• Data de Publicação: 2021
• Outros Autores: Silveira, Gustavo Gil da, Bernardes, César Augusto, CMS Collaboration
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/235206
• topic: Aceleradores de partículas; Bosons Z; Hadron-Hadron scattering (experiments); Top physics

A search for new top quark interactions is performed within the framework of an effective field theory using the associated production of either one or two top quarks with a Z boson in multilepton final states. The data sample corresponds to an integrated luminosity of 138 fb−1 of proton-proton collisions at √ s = 13 TeV collected by the CMS ex periment at the LHC. Five dimension-six operators modifying the electroweak interactions of the top quark are considered. Novel machine-learning techniques are used to enhance the sensitivity to effects arising from these operators. Distributions used for the signal extrac tion are parameterized in terms of Wilson coefficients describing the interaction strengths of the operators. All five Wilson coefficients are simultaneously fit to data and 95% confidence level intervals are computed. All results are consistent with the SM expectations.