First Observation of CP Violation and Measurement of Polarization in B+ → ρ(770)0K*(892)+ Decays



Aaij, R, Abdelmotteleb, ASW, Beteta, C Abellan, Abudinen, F, Ackernley, T, Adefisoye, AA, Adeva, B, Adinolfi, M, Adlarson, P, Agapopoulou, C
et al (show 1176 more authors) (2026) First Observation of CP Violation and Measurement of Polarization in B+ → ρ(770)0K*(892)+ Decays PHYSICAL REVIEW LETTERS, 136 (2). 021803-. ISSN 0031-9007, 1079-7114

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Abstract

An amplitude analysis of the B+→(π+π-)(KS0π+) decay is performed in the mass regions 0.30<mπ+π-<1.10 GeV/c2 and 0.75<mKS0π+<1.20 GeV/c2, using pp collision data recorded with the LHCb detector corresponding to an integrated luminosity of 9 fb-1. The polarization fractions and CP asymmetries for B+→ρ(770)0K∗(892)+ decays are measured. Violation of the CP symmetry in the decay B+→ρ(770)0K∗(892)+ is observed for the first time, with a significance exceeding 9 standard deviations. The CP asymmetry is measured to be ACP=0.507±0.062(stat)±0.024(syst) and the CP-averaged longitudinal polarization fraction of fL=0.720±0.028(stat)±0.009(syst). The measurements help to shed light on the polarization puzzle of B mesons decaying to two vector mesons.

Item Type: Article
Uncontrolled Keywords: LHCb Collaboration
Divisions: Faculty of Science & Engineering
Faculty of Science & Engineering > School of Engineering
Faculty of Science & Engineering > School of Physical Sciences
Faculty of Science & Engineering > School of Physical Sciences > Physics
Faculty of Science & Engineering > School of Engineering > Civil and Environmental Engineering
Depositing User: Symplectic Admin
Date Deposited: 23 Jan 2026 10:01
Last Modified: 16 Jun 2026 20:26
DOI: 10.1103/9zhl-kkwg
Open Access URL: https://journals.aps.org/prl/pdf/10.1103/9zhl-kkwg
Related Websites:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3196689
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