Measurement of the C P-violating phase φs in the B0 s → J/ψφ(1020) → μ+μ− K+K− channel in proton-proton collisions at √s = 13 TeV
The C P-violating weak phase φs and the decay width difference s between the light and heavy B0 s mass eigenstates are measured with the CMS detector at the LHC in a sample of 48 500 reconstructed B0 s → J/ψ φ(1020) → μ+μ− K+K− events. The measurement is based on a data sample corresponding to an in...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | Brasil |
| Institución: | Universidade Federal do Rio Grande do Sul (UFRGS) |
| Repositorio: | Repositório Institucional da UFRGS |
| Idioma: | inglés |
| OAI Identifier: | oai:www.lume.ufrgs.br:10183/241218 |
| Acceso en línea: | http://hdl.handle.net/10183/241218 |
| Access Level: | acceso abierto |
| Palabra clave: | Aceleradores de partículas Colisões proton-proton CMS Physics Oscillations B physics |
| Sumario: | The C P-violating weak phase φs and the decay width difference s between the light and heavy B0 s mass eigenstates are measured with the CMS detector at the LHC in a sample of 48 500 reconstructed B0 s → J/ψ φ(1020) → μ+μ− K+K− events. The measurement is based on a data sample corresponding to an integrated luminosity of 96.4 fb−1, collected in proton-proton collisions at √s = 13 TeV in 2017–2018. To extract the values of φs and s, a time-dependent and flavor-tagged angular analysis of the μ+μ−K+K− final state is performed. The analysis employs a dedicated tagging trigger and a novel opposite-side muon flavor tagger based on machine learning techniques. The measurement yields φs = −11±50 (stat)±10 (syst) mrad and s = 0.114±0.014 (stat)±0.007 (syst) ps−1, in agreement with the standard model predictions. When combined with the previous CMS measurement at √s = 8 TeV, the following values are obtained: φs = −21 ± 44 (stat) ± 10 (syst) mrad, s = 0.1032 ± 0.0095 (stat) ± 0.0048 (syst) ps−1, a significant improvement over the 8 TeV result. |
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