The D mesons are the lightest particle containing charm quarks. They are often studied to gain knowledge on the weak interaction. The

strange Strange may refer to: Fiction * Strange (comic book), a comic book limited series by Marvel Comics * Strange (Marvel Comics), one of a pair of Marvel Comics characters known as The Strangers * Adam Strange, a DC Comics superhero * The title char ...

D mesons (D_s) were called "F mesons" prior to 1986.

Overview

The D mesons were discovered in 1976 by the Mark I detector at the

Stanford Linear Accelerator Center SLAC National Accelerator Laboratory, originally named the Stanford Linear Accelerator Center, is a United States Department of Energy National Laboratory operated by Stanford University under the programmatic direction of the U.S. Departme ...

. Since the D mesons are the lightest mesons containing a single charm

quark A quark () is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. All commonly o ...

(or antiquark), they must change the charm (anti)quark into an (anti)quark of another type to decay. Such transitions involve a change of the internal charm quantum number, and can take place only via the weak interaction. In D mesons, the charm quark preferentially changes into a strange quark via an exchange of a W particle, therefore the D meson preferentially decays into kaons () and pions ().

List of D mesons

‡ PDG reports the resonance width

~\left(\Gamma\right)~.

Here the conversion

\; \tau = \frac \;

is given instead.

CP violation

In 2019, an analysis by the LHCb experiment reported the first observation of CP violation in the decays of the neutral meson, with a significance of over five standard deviations. The results of a subsequent data analysis by the same collaboration was presented in 2022, which announced that they found evidence of direct CP violation in the decay of the meson into pions.

– oscillations

In 2021 it was confirmed with a significance of more than seven standard deviations, that the neutral meson spontaneously transforms into its own antiparticle and back. This phenomenon is called flavor oscillation and was prior known to exist in the neutral

K meson KAON (Karlsruhe ontology) is an ontology infrastructure developed by the University of Karlsruhe and the Research Center for Information Technologies in Karlsruhe. Its first incarnation was developed in 2002 and supported an enhanced version of ...

and B meson.

References

{{Authority control Mesons

Overview

List of D mesons

CP violation

– oscillations

See also

References