A time-integrated angular analysis of the decay Bs0→J/ψK¯∗8920, with J/ψ → μ+μ− and K¯∗8920→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.

Updated measurement of CP violation and polarisation in $$ {B}_s^0\to J/\psi {\overline{K}}^{\ast }{(892)}^0 $$ decays [Updated measurement of CP violation and polarisation in B⁰ₛ → J/ψ K¯* (892)⁰ decays] / R. Aaij, A.S.W.A.. - In: JOURNAL OF HIGH ENERGY PHYSICS. - ISSN 1029-8479. - 2025:10(2025 Oct). [10.1007/jhep10(2025)173]

Updated measurement of CP violation and polarisation in $$ {B}_s^0\to J/\psi {\overline{K}}^{\ast }{(892)}^0 $$ decays [Updated measurement of CP violation and polarisation in B⁰ₛ → J/ψ K¯* (892)⁰ decays]

S. Cesare;C. Mancuso;D. Marangotto;A. Merli;N. Neri;G. Tonani;T. Tork;Z. Wang;
2025

Abstract

A time-integrated angular analysis of the decay Bs0→J/ψK¯∗8920, with J/ψ → μ+μ− and K¯∗8920→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.
B Physics; CP Violation; Hadron-Hadron Scattering; Polarization;
Settore PHYS-01/A - Fisica sperimentale delle interazioni fondamentali e applicazioni
ott-2025
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/1252375
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