Measurement of CP Violation Observables in D^{+}→K^{-}K^{+}π^{+} Decays

Area of Science:

• Particle Physics
• High Energy Physics
• Symmetry Violations

Background:

• Charge-Parity (CP) symmetry is a fundamental principle in particle physics.
• Understanding CP violation is crucial for explaining the matter-antimatter asymmetry in the universe.
• The D+→K-K+π+ decay offers a unique channel to probe CP symmetry.

Purpose of the Study:

• To search for violations of CP symmetry in the D+→K-K+π+ decay.
• To measure CP asymmetry observables in this decay channel.
• To set new limits on CP violation in multibody decays.

Main Methods:

• Utilized proton-proton collision data from the LHCb detector at 13 TeV.
• Employed a novel model-independent technique to compare D+ and D- phase-space distributions.
• Subtracted instrumental asymmetries using the D_s+→K-K+π+ control channel.

Main Results:

• The p-value for the hypothesis of CP conservation is 8.1%.
• Measured CP asymmetry observables: A_CP|S^ϕπ+ = (0.95±0.43_stat±0.26_syst)×10^-3 and A_CP|S^K*0K+ = (-0.26±0.56_stat±0.18_syst)×10^-3.
• No evidence for CP violation was observed.

Conclusions:

• The results show no evidence of CP violation in the D+→K-K+π+ decay.
• This represents the most sensitive search for CP violation in the phase space of a multibody decay to date.
• The findings contribute to the ongoing investigation of fundamental symmetries in particle physics.