Based on its mass (3,872 million electron volts) and the particles it decayed into, X(3872) appeared to consist of a charm quark
, an anticharm and at least two other quarks.
c] meson contains a charm quark
and a bottom antiquark.
Combing data from millions of collisions that occurred between 1996 and 2000, the H1 researchers found evidence for about 50 appearances of a pentaquark containing a charm quark
, says team spokesman Max Klein.
Each of the newfound particles, designated respectively as Ds(2317) and Ds (2463), is a so-called Ds meson, which contains a charm quark
and an antimatter quark called antistrange.
The scientists have often created baryons containing two and even three strange quarks, but no one had ever detected a baryon containing more than one charm quark
, at least no one thought so.
The Fermilab discovery fills in the final blank: a meson consisting of a charm quark
and an antibottom quark.
They expect to probe the gluon content of the proton by firing high-energy muons at polarized targets and looking for ejected mesons containing the charm quark
A J/y particle, a meson that consists of a charm quark
and its antiparticle counterpart, has such a large mass that it rarely forms in proton-proton collisions, the standard experiment in high-energy physics.