D0

D0 is the neutral D meson in particle physics. It consists of a charm quark and an up antiquark (c ū), and its antiparticle is the anti-D0, made of an anti-charm quark and an up quark (c̄ u). As a charm meson, the D0 is a bound state of quarks held together by the strong interaction, but its decays proceed through the weak interaction. The D0 meson and anti-D0 are distinct flavor states, but they can mix, leading to oscillations between the two.

The D0 is produced in a variety of high-energy processes, including electron-positron annihilation, hadron collisions, and heavy-ion collisions. It decays primarily via weak decay channels, with common hadronic modes such as D0 → K− π+ (a Cabibbo-favored decay), as well as other multi-body hadronic decays and semileptonic decays. The lifetime of the D0 is about 0.41 picoseconds, making it relatively short-lived on human time scales but measurable with modern detectors.

A key feature of D0 physics is D0–D̄0 mixing, in which the flavor eigenstates convert into each other over time. This mixing is described by parameters x and y, related to the mass and width differences of the D0–D̄0 system, and is small but experimentally observable. CP violation in D0 decays is expected to be small in the Standard Model, so measurements of asymmetries provide important tests for new physics.

D0 mesons are central to studies of charm-quark dynamics, hadronization, and the behavior of weak decays in the charm sector, offering insights into flavor physics and the limits of the Standard Model.