A time-integrated angular analysis of the decay B0s → J/ψ anti-K*(892)0, with J/ψ → μ+ μ− and anti-K*(892)0 → K− π+, is presented. The analysis employs a sample of proton-proton collision data collected by the LHCb experiment during 2015-2018 at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb^−1. A simultaneous maximum-likelihood fit is performed to the angular distributions in bins of the K− π+ mass. This fit yields measurements of the CP-averaged polarisation fractions and CP asymmetries for the P-wave component of the K− π+ system. The longitudinal and parallel polarisation fractions are determined to be f_0 = 0.534 ± 0.012 ± 0.009 and f_∥ = 0.211 ± 0.014 ± 0.005, respectively, where the first uncertainty is statistical and the second is systematic. The CP asymmetries are measured with 3-7% precision and are found to be consistent with zero. These measurements, along with an updated determination of the branching fraction relative to the B0 → J/ψ K*0 decay, are combined with previous LHCb results, providing the most precise values for these observables to date.

Aaij, R., Abdelmotteleb, A.S.W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adefisoye, A.A., et al. (2025). Updated measurement of CP violation and polarisation in B0s → J/ψ anti-K*(892)0 decays. JOURNAL OF HIGH ENERGY PHYSICS, 2025(10), 0-34 [10.1007/jhep10(2025)173].

Updated measurement of CP violation and polarisation in B0s → J/ψ anti-K*(892)0 decays

Carbone, A.;Ferrari, F.;Galli, D.;Patrignani, C.;Spedicato, E.;Villa, A.;Zenesini, F.;
2025

Abstract

A time-integrated angular analysis of the decay B0s → J/ψ anti-K*(892)0, with J/ψ → μ+ μ− and anti-K*(892)0 → K− π+, is presented. The analysis employs a sample of proton-proton collision data collected by the LHCb experiment during 2015-2018 at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb^−1. A simultaneous maximum-likelihood fit is performed to the angular distributions in bins of the K− π+ mass. This fit yields measurements of the CP-averaged polarisation fractions and CP asymmetries for the P-wave component of the K− π+ system. The longitudinal and parallel polarisation fractions are determined to be f_0 = 0.534 ± 0.012 ± 0.009 and f_∥ = 0.211 ± 0.014 ± 0.005, respectively, where the first uncertainty is statistical and the second is systematic. The CP asymmetries are measured with 3-7% precision and are found to be consistent with zero. These measurements, along with an updated determination of the branching fraction relative to the B0 → J/ψ K*0 decay, are combined with previous LHCb results, providing the most precise values for these observables to date.
2025
Aaij, R., Abdelmotteleb, A.S.W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adefisoye, A.A., et al. (2025). Updated measurement of CP violation and polarisation in B0s → J/ψ anti-K*(892)0 decays. JOURNAL OF HIGH ENERGY PHYSICS, 2025(10), 0-34 [10.1007/jhep10(2025)173].
Aaij, R.; Abdelmotteleb, A. S. W.; Abellan Beteta, C.; Abudinén, F.; Ackernley, T.; Adefisoye, A. A.; Adeva, B.; Adinolfi, M.; Adlarson, P.; Agapopoul...espandi
File in questo prodotto:
File Dimensione Formato  
2025-AR-50-Upd_Meas_of_CP_Viol_and_Pol_in_B0s-JHEP.pdf

accesso aperto

Tipo: Versione (PDF) editoriale / Version Of Record
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione (CCBY)
Dimensione 1.02 MB
Formato Adobe PDF
1.02 MB Adobe PDF Visualizza/Apri

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/11585/1036267
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 0
social impact