New BaBar results are a strong verification of the predictions of the Standard Model of particles, demonstrating that—at least for some elementary particle processes—the direction of time matters.

Unlike our daily experience, the world of elementary particle physics is mostly symmetrical in time. Run the clock backward on your day and it won't work; run the clock backward on a process in particle physics and things are just fine. However, to preserve certain fundamental aspects of space-time the Standard Model predicts that certain reversible events nevertheless have different probabilities, depending on which way they go.

Finding a direction of time in exotic particle transformations: Entangled B mesons show that time has an arrow on the smallest scales by Matthew Francis, Ars Technica