LHCb Collaboration Reports on C P Violation in D+ Decays

A recent paper titled "Measurement of C P violation observables in D+ → K−K+π+ decays" has been published by the LHCb collaboration, which includes R. Aaij and over 1,100 co-authors. The study investigates the charge-parity (C P) symmetry in the decay process of D+ mesons into K−K+π+ particles. This research utilizes data from proton-proton collisions at a center-of-mass energy of 13 TeV, with an integrated luminosity of 5.4 fb−1 collected by the LHCb detector.

The authors employed a novel model-independent technique to compare the phase-space distributions of D+ and D− decays. They also used the decay channel D+_s → K−K+π+ as a control to subtract instrumental asymmetries. The results yielded a p-value of 8.1% for the hypothesis of C P conservation, indicating no significant evidence of C P violation in the observed decays.

The measured C P asymmetry observables were reported as follows:

• A_{C P|S}^{φπ+} = (0.95 ± 0.43_{stat} ± 0.26_{syst}) × 10^{-3}
• A_{C P|S}^{K*0K+} = (-0.26 ± 0.56_{stat} ± 0.18_{syst}) × 10^{-3}

These findings represent the most sensitive search for C P violation in the phase space of a multibody decay to date. The implications of this research are significant for the understanding of fundamental symmetries in particle physics, particularly in the context of the Standard Model and beyond. The full paper can be accessed via arXiv:2409.01414.