A time-integrated angular analysis of the decay Bs0→J/ψK¯∗(892), with J/ψ → μ+μ− and K¯∗(892)→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 f0 = 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/ψK*0 decay, are combined with previous LHCb results, providing the most precise values for these observables to date.

Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., Adefisoye, A., et al. (2025). Updated measurement of CP violation and polarisation in Bs0→J/ψK¯∗8920 decays. JOURNAL OF HIGH ENERGY PHYSICS, 2025(10) [10.1007/JHEP10(2025)173].

Updated measurement of CP violation and polarisation in Bs0→J/ψK¯∗8920 decays

Anelli A.;Borsato M.;Calvi M.;Capelli S.;Carniti P.;Falcao L. N.;Fazzini D.;Garcia Pardinas J.;Gotti C.;Kirsebom V. S.;Malentacca L.;Martinazzoli L.;Martinelli M.;Minotti A.;Pizzichemi M.;Salomoni M.;
2025

Abstract

A time-integrated angular analysis of the decay Bs0→J/ψK¯∗(892), with J/ψ → μ+μ− and K¯∗(892)→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 f0 = 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/ψK*0 decay, are combined with previous LHCb results, providing the most precise values for these observables to date.
Articolo in rivista - Articolo scientifico
B Physics; CP Violation; Hadron-Hadron Scattering; Polarization;
English
21-ott-2025
2025
2025
10
173
none
Aaij, R., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., Adefisoye, A., et al. (2025). Updated measurement of CP violation and polarisation in Bs0→J/ψK¯∗8920 decays. JOURNAL OF HIGH ENERGY PHYSICS, 2025(10) [10.1007/JHEP10(2025)173].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

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/10281/589887
Citazioni
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 0
Social impact