First measurement of the decay-time-integrated C P asymmetry in B_s⁰ → D_s^- π⁺ decays

2026/03/11 by LHCb collaboration, R. Aaij, M. Abdelfatah +1114 · 2 voices
#hep-ex

paper · pdf

Abstract

A measurement of the flavour-untagged decay-time-integrated C P asymmetry in the flavour-specific decay B_s⁰ → D_s^-π⁺, ⟨ A^s_{\rm untagged}⟩, is performed using proton-proton collision data collected by the LHCb experiment between 2016 and 2018 at a center-of-mass energy of 13 \rm TeV, corresponding to a total integrated luminosity of 5.4 \rm fb^-1. The C P asymmetry is measured in two D_s^- meson decay modes, D_s^- → K^-K⁺π^- and D_s^- → π^-π⁺π^-. The combined result, ⟨ A^s_{\rm untagged}⟩ = ( -1.4 ± 5.9 \rm(stat) ± 1.1 \rm(syst)) × 10^-3, is consistent with the Standard Model expectation and provides a direct constraint on new physics in tree-level b-hadron decays.

Citations

• The LHCb Stripping Project: Sustainable Legacy Data Processing for High-Energy Physics
• The LHCb Sprucing and Analysis Productions
• Geant4 developments and applications

Discussions

• First measurement of the decay-time-integrated CP asymmetry in Bₛ⁰→Dₛ⁻π⁺ decays arxiv.org/abs/2603.10860 - The combined result, (−1.4±5.9(stat)±1.1(syst))×10⁻³, is consistent with the Standard Model e [bsky, 5 points, 0 comments]
• #LHCbpaper: First measurement of the decay-time-integrated CP asymmetry in B⁰_s → D⁻_s π⁺ decays (arXiv:2603.10860) https://arxiv.org/abs/2603.10860 [bsky, 1 points, 0 comments]

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• First Evidence of the B s 0 → K − π + γ Decay