Observation of several sources of $CP$ violation in $B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}$ decays

Abstract

An amplitude analysis of $B^{+}\to K^{+}{\pi }^{+}{\pi }^{-}$ decays is presented in which six $CP$-violating phenomena are judged to be of significance for the first time. This analysis is based on $pp$ collision data recorded with the LHCb detector in 2011-2012, corresponding to an integrated luminosity of $3{\text{fb}}^{-1}$. Quasi-two-body $CP$ violation in $B^{+}\to \rho (770{)}^0{K}^{+}$ decays is discovered, while $CP$ violation at amplitude level is established in $B^{+}\to f_2(1270)K^{+}$ decays. First evidence for $CP$ violation is reported in both the fully elastic S-wave $\pi \pi$-$\pi \pi$ rescattering region and also for any decay involving a spin-3 resonance. Additionally, significant $CP$-violation effects are identified in the interference between different $\pi \pi$ partial waves, with observation in S-P wave interference and evidence in S-D wave interference, both of which must be driven by long-distance interactions.

All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://lhcb-glance.cern.ch/alcm/public/analysis/full-details/5752/ (LHCb public pages)