Search for CP violation in tt ¯ H and tH production in multilepton channels in proton-proton collisions at √s = 13 TeV

The charge-parity (CP) structure of the Yukawa interaction between the Higgs (H) boson and the top quark is measured in a data sample enriched in the t¯tH and tH associated production, using 138 fb−¹ of data collected in proton-proton collisions at √s = 13 TeV by the CMS experiment at the CERN LHC....

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Detalles Bibliográficos
Autores: Tumasyan, A., Brochero Cifuentes, Javier Andrés|||0000-0003-2093-7856, Cabrillo Bartolomé, José Iban, Calderón Tazón, Alicia|||0000-0002-7205-2040, Duarte Campderros, Jorge|||0000-0003-0687-5214, Fernández García, Marcos|||0000-0002-4824-1087, Fernández Madrazo, Celia|||0000-0001-9748-4336, García Alonso, Andrea, Gómez Gramuglio, Gervasio|||0000-0002-1077-6553, Lasaosa García, Clara, Martínez Rivero, Celso, Martínez Ruiz del Árbol, Pablo|||0000-0002-7737-5121, Matorras Weinig, Francisco|||0000-0003-4295-5668, Matorras Cuevas, Pablo|||0000-0001-7481-7273, Piedra Gómez, Jonatan|||0000-0002-9157-1700, Prieëls, Cedric, Ruiz Jimeno, Alberto|||0000-0002-3639-0368, Scodellaro, Luca|||0000-0002-4974-8330, Vila Álvarez, Iván |||0000-0002-6797-7209, Vizán García, Jesús Manuel|||0000-0002-6823-8854
Tipo de recurso: artículo
Fecha de publicación:2023
País:España
Institución:Universidad de Cantabria (UC)
Repositorio:UCrea Repositorio Abierto de la Universidad de Cantabria
Idioma:inglés
OAI Identifier:oai:repositorio.unican.es:10902/32583
Acceso en línea:https://hdl.handle.net/10902/32583
Access Level:acceso abierto
Palabra clave:CP Violation
Hadron-Hadron Scattering
Higgs Physics
Descripción
Sumario:The charge-parity (CP) structure of the Yukawa interaction between the Higgs (H) boson and the top quark is measured in a data sample enriched in the t¯tH and tH associated production, using 138 fb−¹ of data collected in proton-proton collisions at √s = 13 TeV by the CMS experiment at the CERN LHC. The study targets events where the H boson decays via H → WW or H → ττ and the top quarks decay via t → Wb: the W bosons decay either leptonically or hadronically, and final states characterized by the presence of at least two leptons are studied. Machine learning techniques are applied to these final states to enhance the separation of CP-even from CP-odd scenarios. Two-dimensional confidence regions are set on κt and ˜κt, which are respectively defined as the CP-even and CP-odd top-Higgs Yukawa coupling modifiers. No significant fractional CP-odd contributions, parameterized by the quantity |fCPHtt| are observed; the parameter is determined to be |fCPHtt| = 0.59 with an interval of (0.24, 0.81) at 68% confidence level. The results are combined with previous results covering the H → ZZ and H → γγ decay modes, yielding two- and one-dimensional confidence regions on κt and ˜κt, while |fCPHtt| is determined to be |fCPHtt| = 0.28 with an interval of |fCPHtt| < 0.55 at 68% confidence level, in agreement with the standard model CP-even prediction of |fCPHtt| = 0.

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