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.

Measurement of the CP-violating phase ϕs in the Bs0→J/ψϕ(1020)→μ+μ−K+K− channel in proton-proton collisions at s=13TeV / 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., Lechner, L., Liko, D., Madlener, T., Mikulec, I., Pitters, F.M., Rad, N., Schieck, J., Schofbeck, R., Spanring, M., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 816:(2021), p. 136188. [10.1016/j.physletb.2021.136188]

Measurement of the CP-violating phase ϕs in the Bs0→J/ψϕ(1020)→μ+μ−K+K− channel in proton-proton collisions at s=13TeV

Cipriani M.;Del Re D.;Longo E.;Organtini G.;Paramatti R.;Quaranta C.;Rahatlou S.;Santanastasio F.;Tramontano R.;
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
B physics; CMS; Oscillations; Physics
01 Pubblicazione su rivista::01a Articolo in rivista
Measurement of the CP-violating phase ϕs in the Bs0→J/ψϕ(1020)→μ+μ−K+K− channel in proton-proton collisions at s=13TeV / 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., Lechner, L., Liko, D., Madlener, T., Mikulec, I., Pitters, F.M., Rad, N., Schieck, J., Schofbeck, R., Spanring, M., et al.. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 816:(2021), p. 136188. [10.1016/j.physletb.2021.136188]
File allegati a questo prodotto
File Dimensione Formato  
Sirunyan_Measurement of the C P-violating_2021.pdf

accesso aperto

Tipologia: Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza: Creative commons
Dimensione 984.11 kB
Formato Adobe PDF
984.11 kB Adobe PDF

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1627652
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 51
  • ???jsp.display-item.citation.isi??? 36
social impact