The CP -violating weak phase ϕs and the decay width difference ΔΓs between the light and heavy Bs0 mass eigenstates are measured with the CMS detector at the LHC in a sample of 48500 reconstructed Bs0→J/ψϕ(1020)→μ+μ−K+K− events. The measurement is based on a data sample corresponding to an integrated luminosity of 96.4fb−1, collected in proton-proton collisions at √s =13TeV in 2017–2018. To extract the values of ϕs and ΔΓs, 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 ΔΓs=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 =8TeV, the following values are obtained: ϕs=−21±44(stat)±10(syst)mrad, ΔΓs=0.1032±0.0095(stat)±0.0048(syst)ps−1, a significant improvement over the 8 TeV result.

Sirunyan A.M., Tumasyan A., Adam W., Ambrogi F., Bergauer T., Dragicevic M., et al. (2021). Measurement of the C P -violating phase φs in the B0s → J/ψ φ(1020) → μ+μ− K+K− channel in proton-proton collisions at √s = 13 TeV. PHYSICS LETTERS. SECTION B, 816, 1-27 [10.1016/j.physletb.2021.136188].

Measurement of the C P -violating phase φs in the B0s → J/ψ φ(1020) → μ+μ− K+K− channel in proton-proton collisions at √s = 13 TeV

Battilana C.;Bonacorsi D.;Borgonovi L.;Braibant-Giacomelli S.;Castro A.;Cuffiani M.;Diotalevi T.;Fanfani A.;Fontanesi E.;Guiducci L.;Iemmi F.;Primavera F.;Rovelli T.;Siroli G. P.;
2021

Abstract

The CP -violating weak phase ϕs and the decay width difference ΔΓs between the light and heavy Bs0 mass eigenstates are measured with the CMS detector at the LHC in a sample of 48500 reconstructed Bs0→J/ψϕ(1020)→μ+μ−K+K− events. The measurement is based on a data sample corresponding to an integrated luminosity of 96.4fb−1, collected in proton-proton collisions at √s =13TeV in 2017–2018. To extract the values of ϕs and ΔΓs, 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 ΔΓs=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 =8TeV, the following values are obtained: ϕs=−21±44(stat)±10(syst)mrad, ΔΓs=0.1032±0.0095(stat)±0.0048(syst)ps−1, a significant improvement over the 8 TeV result.
2021
Sirunyan A.M., Tumasyan A., Adam W., Ambrogi F., Bergauer T., Dragicevic M., et al. (2021). Measurement of the C P -violating phase φs in the B0s → J/ψ φ(1020) → μ+μ− K+K− channel in proton-proton collisions at √s = 13 TeV. PHYSICS LETTERS. SECTION B, 816, 1-27 [10.1016/j.physletb.2021.136188].
Sirunyan A.M.; Tumasyan A.; Adam W.; Ambrogi F.; Bergauer T.; Dragicevic M.; Ero J.; Escalante Del Valle A.; Fruhwirth R.; Jeitler M.; Krammer N.; Lec...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/853304
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