2019/20 Lessons from τ (Ω_c⁰) \& τ (Xi_c⁰) and {bf CP} asymmetry in charm decays
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Our 2003 "Cicerone" had discussed charm dynamics with different directions and levels \cite{CICERONE}. Here we focus on two items, where the `landscape' has changed sizably. (A) The lifetimes \& semi-leptonic decays of charm hadrons show the impact of non-perturbative QCD and to which degree one can apply Heavy Quark Expansion (HQE) for charm hadrons. It is more complex as we have learnt from 2019/20 data. (B) {\bf CP} asymmetry has been established in 2019 \cite{LHCbGuy}: $\Delta A_{\bf CP} \equiv A_{\bf CP}(D^0 \to K^+K^-) - A_{\bf CP}(D^0 \to \pi^+\pi^-) $=$\, -\, (1.54 \pm 0.29 ) \cdot 10^{-3}$ is quite an achievement by the LHCb collaboration! Our community is at the beginning of a long travel for fundamental dynamics. Can the SM account for these? We discuss the assumptions that were made up to 2018 data and new conclusions from 2019/20 ones. We need more data; however, one has to discuss correlations between different transitions. We give an {\bf Appendix} what we have learnt for large {\bf CP} asymmetry in $K_L \to \pi^+\pi^-e^+e^-$.
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Study of doubly heavy baryon lifetimes
Lifetimes of Xi_cc++, Xi_cc+, Omega_cc+ are (2.67 ± 0.94, 0.47 ± 0.08, 1.79 ± 0.62) × 10^{-13} s and for Xi_bb0, Xi_bb-, Omega_bb- are (0.75 ± 0.11, 0.92 ± 0.15, 0.93 ± 0.15) × 10^{-12} s, with W-exchange driving larg...
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