TY - JOUR
T1 - Updated measurement of CP violation and polarisation in Bs0→J/ψK¯∗8920 decays
AU - The LHCb collaboration
AU - Aaij, R.
AU - Abdelmotteleb, A. S.W.
AU - Abellan Beteta, C.
AU - Abudinén, F.
AU - Ackernley, T.
AU - Adefisoye, A. A.
AU - Adeva, B.
AU - Adinolfi, M.
AU - Adlarson, P.
AU - Agapopoulou, C.
AU - Aidala, C. A.
AU - Ajaltouni, Z.
AU - Akar, S.
AU - Akiba, K.
AU - Albicocco, P.
AU - Albrecht, J.
AU - Aleksiejunas, R.
AU - Alessio, F.
AU - Aliouche, Z.
AU - Alvarez Cartelle, P.
AU - Amalric, R.
AU - Amato, S.
AU - Amey, J. L.
AU - Amhis, Y.
AU - An, L.
AU - Anderlini, L.
AU - Andersson, M.
AU - Andreola, P.
AU - Andreotti, M.
AU - Andres Estrada, S.
AU - Anelli, A.
AU - Ao, D.
AU - Archilli, F.
AU - Areg, Z.
AU - Argenton, M.
AU - Arguedas Cuendis, S.
AU - Artamonov, A.
AU - Artuso, M.
AU - Aslanides, E.
AU - Ataíde Da Silva, R.
AU - Atzeni, M.
AU - Audurier, B.
AU - Authier, J. A.
AU - Bacher, D.
AU - Bachiller Perea, I.
AU - Bachmann, S.
AU - Bachmayer, M.
AU - Back, J. J.
AU - Baladron Rodriguez, P.
AU - Calderon Ramirez, S.
N1 - Publisher Copyright:
© The Author(s) 2025.
PY - 2025/10
Y1 - 2025/10
N2 - 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.
AB - 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.
KW - B Physics
KW - CP Violation
KW - Hadron-Hadron Scattering
KW - Polarization
UR - https://www.scopus.com/pages/publications/105025377786
U2 - 10.1007/JHEP10(2025)173
DO - 10.1007/JHEP10(2025)173
M3 - Artículo
AN - SCOPUS:105025377786
SN - 1029-8479
VL - 2025
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
IS - 10
M1 - 173
ER -