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Charming clue for our existence

The Large Hadron Collider beauty experiment (LHCb) collaboration announced the observation of charge parity (CP) violation in the decays of the D0 meson, the lightest particle containing charm quarks, which might provide clues to why there is more matter than antimatter in the Universe and lead to a deeper understanding of the theory of the strong interaction.

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  1. 1.

    Sakharov, A. D. Violation of CP Invariance, C asymmetry, and baryon asymmetry of the universe. J. Exp. Theor. Phys. 5, 24–27 (1967).

  2. 2.

    Kobayashi, M. & Maskawa, T. CP violation in the renormalizable theory of weak interaction. Prog. Theor. Phys. 49, 652–657 (1973).

  3. 3.

    LHCb collaboration. Evidence for CP violation in time-integrated D0 → h+h decay rates. Phys. Rev. Lett. 108, 111602 (2012).

  4. 4.

    Lenz, A. What did we learn in theory from the ΔACP-saga? Preprint at arXiv (2013).

  5. 5.

    LHCb collaboration. Observation of CP violation in charm decays. Preprint at arXiv (2019).

  6. 6.

    Chala, M. et al. ΔACP within the standard model and beyond. Preprint at arXiv (2019).

  7. 7.

    Grossman, Y. & Schacht, S. The emergence of the ΔU = 0 rule in charm physics. Preprint at arXiv (2019).

  8. 8.

    Li, H.-N., Lü, C.-D. & Yu, F.-S. Implications on the first observation of charm CPV at LHCb. Preprint at arXiv (2019).

  9. 9.

    Kirk, M., Lenz, A. & Rauh, T. Dimension-six matrix elements for meson mixing and lifetimes from sum rules. J. High Energy Phys. 1712, 068 (2017).

  10. 10.

    Khodjamirian, A. & Petrov, A. A. Direct CP asymmetry in D0 → ππ+ and D0 → KK+ in QCD-based approach. Phys. Lett. B 774, 235 (2017).

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The authors declare no competing interests.

Correspondence to Alexander Lenz.

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Fig. 1: Six different types of quarks are known to exist in nature.