Measurement of the CP-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 B 2021
Viesturs Veckalns

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.

Atslēgas vārdi
B physics | CMS | Oscillations | Physics
DOI
10.1016/j.physletb.2021.136188
Hipersaite
https://www.sciencedirect.com/science/article/pii/S0370269321001283?via%3Dihub

CMS Collaboration, A.M.Sirunyan, A.Tumasyan, V.Veckalns ... [et al.] Measurement of the CP-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 B, 2021, Vol. 816, Article number 136188. ISSN 0370-2693. Available from: doi:10.1016/j.physletb.2021.136188

Publikācijas valoda
English (en)