LHCb Collaboration:Adeva Andany, BernardoÁlvarez Cartelle, PaulaBorsato, MartinoChobanova, VeronikaCid Vidal, XabierDosil Suárez, ÁlvaroFernández Prieto, AntonioGallas Torreira, AbrahamGarcía Pardiñas, JuliánLemos Cid, EdgarLucio Martinez, M.Martínez Santos, DiegoPló Casasús, MáximoPrisciandaro, JessicaRamos Pernas, MiguelRomero Vidal, AntonioSaborido Silva, Juan JoséSanmartín Sedes, BraisSantamarina Ríos, CibránVázquez Regueiro, PabloVieites Díaz, María2026-01-122026-01-122018-03-23The LHCb collaboration., Aaij, R., Adeva, B. et al. First measurement of the CP-violating phase in B 0 s  → (K+π−)(K−π+) decays. J. High Energ. Phys. 2018, 140 (2018). https://doi.org/10.1007/JHEP03(2018)140https://hdl.handle.net/10347/45048A flavour-tagged decay-time-dependent amplitude analysis of Bs0 →(K+π−)(K−π+) decays is presented in the K±π∓ mass range from 750 to 1600MeV/c2. The analysis uses pp collision data collected with the LHCb detector at centre-of-mass energies of 7 and 8TeV, corresponding to an integrated luminosity of 3.0fb−1. Several quasi-two-body decay modes are considered, corresponding to K±π∓ combinations with spin 0, 1 and 2, which are dominated by the K0∗ (800)0 and K0∗ (1430)0 , the K ∗ (892)0 and the K2∗(1430)0 resonances, respectively. The longitudinal polarisation fraction for the Bs0 → K ∗ (892)0 K ∗ (892)0 decay is measured as fL = 0.208 ± 0.032 ± 0.046, where the first uncertainty is statistical and the second is systematic. The first measurement of the dd mixing-induced CP-violating phase, φs , in b → dds transitions is performed, yielding a value of φdd ̄ = −0.10 ± 0.13 (stat) ± 0.14 (syst) radeng© 2026 Springer Nature. This article is licensed under a Creative Commons Attribution 4.0 International LicenseAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/CP violationFlavour Changing Neutral CurrentsB physicsOscillationHadron-Hadron scattering (experiments)journal article10.1007/JHEP03(2018)1401029-8479open access