Quantum speed of evolution of neutral mesons

We investigate the quantum-mechanical time-evolution speed limit for neutral $K$ and $B$ mesons, both single as well as correlated, within the framework of open quantum systems. The role of coherence--mixing, a crucial feature of the open system evolution of the underlying quantum systems (here, the mesons), on the quantum-mechanical time-evolution speed limit is studied. The impact of decoherence and CP (charge conjugation parity) symmetry violation on quantum-mechanical time-evolution speed limit is also investigated. The quantum-mechanical time-evolution speed limit increases with the evolution time for the single mesons, a signature of the underlying open system dynamics of the evolution being semi-group in nature. The evolution of the correlated mesons slows down for an evolution time of approximately one-fourth of the lifetime, after which it is sped up. An overall pattern that emerges is that correlated mesons evolve faster as compared to their uncorrelated counterparts, suggesting that quantum correlations can speed up evolution.