Combinations of single-top-quark production cross-section measurements and |ƒ_LVV_tb| determinations at √s = 7 and 8 TeV with the ATLAS and CMS experiments

• Autores: Alconada Verzini, María Josefina; Alonso, Francisco; Arduh, Francisco Anuar; Dova, María Teresa; Hoya, Joaquín; Monticelli, Fernando Gabriel; Orellana, Gonzalo Enrique; Wahlberg, Hernán Pablo; The ATLAS and CMS collaborations
• Año de publicación: 2019
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Física; Hadron-Hadron scattering (experiments)
• Institución: Universidad Nacional de La Plata

This paper presents the combinations of single-top-quark production cross-section measurements by the ATLAS and CMS Collaborations, using data from LHC proton-proton collisions at s√ = 7 and 8 TeV corresponding to integrated luminosities of 1.17 to 5.1 fb⁻¹ at s√ = 7 TeV and 12.2 to 20.3 fb⁻¹ at s√ = 8 TeV. These combinations are performed per centre-of-mass energy and for each production mode: t-channel, tW, and s-channel. The combined t-channel cross-sections are 67.5 ± 5.7 pb and 87.7 ± 5.8 pb at s√ = 7 and 8 TeV respectively. The combined tW cross-sections are 16.3 ± 4.1 pb and 23.1 ± 3.6 pb at s√ = 7 and 8 TeV respectively. For the s-channel cross-section, the combination yields 4.9 ± 1.4 pb at s√ = 8 TeV. The square of the magnitude of the CKM matrix element V_tb multiplied by a form factor ƒ_LV is determined for each production mode and centre-of-mass energy, using the ratio of the measured cross-section to its theoretical prediction. It is assumed that the top-quark-related CKM matrix elements obey the relation |V_td|, |V_ts| ≪ |V_tb|. All the ƒ_LVV_tb|² determinations, extracted from individual ratios at s√ = 7 and 8 TeV, are combined, resulting in |ƒ_LVV_tb| = 1.02 ± 0.04 (meas.) ± 0.02 (theo.). All combined measurements are consistent with their corresponding Standard Model predictions.
Instituto de Física La Plata