A model-independent measurement of the CKM angle γ in the decays B ± → [ K + K − π + π − ] D h ± and B ± → [ π + π − π + π − ] D h ± ( h = K, π )

Journal article

A model-independent determination of the CKM angle γ is presented, using the B± → [K+K−π+π−]Dh± and B± → [π+π−π+π−]Dh± decays, with h = K, π. This measurement is the first phase-space binned study of these decay modes, and uses a sample of proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1. The phase-space bins are optimised for sensitivity to γ, and in each bin external inputs from the BESIII experiment are used to constrain the charm strong-phase parameters. The result of this binned analysis is γ=53.9−8.9+9.5°, where the uncertainty includes both statistical and systematic contributions. Furthermore, when combining with existing phase-space integrated measurements of the same decay modes, a value of γ=52.6−6.4+8.5° is obtained, which is one of the most precise determinations of γ to date.

Authors: Aaij, R; Abdelmotteleb, ASW; Abellan Beteta, C; Abudinén, F; Ackernley, T

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer
• Journal: Journal of High Energy Physics
• Volume: 2026
• Issue: 1
• Article number: 62
• Publication date: 2026-01-09
• Acceptance date: 2025-11-03
• DOI: 10.1007/jhep01(2026)062
• EISSN: 1029-8479
• ISSN: 1126-6708
• Language: English
• Keywords: CKM Angle Gamma; B Physics; CP Violation; Hadron-Hadron Scattering