Z(4430)
Encyclopedia
Z is a meson
ic resonance
discovered by the Belle experiment
.. It has a mass of . This resonance has not yet been seen in other experiments.
Unlike the X(3872)
meson discovered by the same experiment, this particle has a charge and is a tetraquark
meson candidate. However, its quantum numbers seem to be those of a pion
, which is inconsistent with the tetraquark interpretation.
Meson
In particle physics, mesons are subatomic particles composed of one quark and one antiquark, bound together by the strong interaction. Because mesons are composed of sub-particles, they have a physical size, with a radius roughly one femtometer: 10−15 m, which is about the size of a proton...
ic resonance
Resonance (particle physics)
In particle physics, a resonance is the peak located around a certain energy found in differential cross sections of scattering experiments. These peaks are associated with subatomic particles and their excitations...
discovered by the Belle experiment
Belle experiment
The Belle experiment is a particle physics experiment conducted by the Belle Collaboration, an international collaboration of more than 400 physicists and engineers investigating CP-violation effects at the High Energy Accelerator Research Organisation in Tsukuba, Ibaraki Prefecture, Japan.The...
.. It has a mass of . This resonance has not yet been seen in other experiments.
Unlike the X(3872)
X(3872)
The X is an anomalous particle with an energy of 3871.2 MeV which does not fit into the quark model because of its quantum numbers. It was discovered by the Belle experiment in Japan and later confirmed by several other experimental collaborations. Several theories have been proposed for its...
meson discovered by the same experiment, this particle has a charge and is a tetraquark
Tetraquark
In particle physics a tetraquark is a hypothetical meson composed of four valence quarks. In principle, a tetraquark state may be allowed in quantum chromodynamics, the modern theory of strong interactions. However, there has been no confirmed report of a tetraquark state to date...
meson candidate. However, its quantum numbers seem to be those of a pion
Pion
In particle physics, a pion is any of three subatomic particles: , , and . Pions are the lightest mesons and they play an important role in explaining the low-energy properties of the strong nuclear force....
, which is inconsistent with the tetraquark interpretation.