The double-charm tetraquark (T, cc) is a type of long-lived

tetraquark A tetraquark, in particle physics, is an exotic meson composed of four valence quarks. A tetraquark state has long been suspected to be allowed by quantum chromodynamics, the modern theory of strong interactions. A tetraquark state is an examp ...

that was discovered in 2021 in the

LHCb The LHCb (Large Hadron Collider beauty) experiment is one of eight particle physics detector experiments collecting data at the Large Hadron Collider at CERN. LHCb is a specialized b-physics experiment, designed primarily to measure the paramet ...

experiment conducted at the

Large Hadron Collider The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundred ...

. It contains four

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 ...

s: two

charm quark The charm quark, charmed quark or c quark (from its symbol, c) is the third-most massive of all quarks, a type of elementary particle. Charm quarks are found in hadrons, which are subatomic particles made of quarks. Examples of hadrons containin ...

s, an anti-up and an anti-down quark. It has a theoretical computed mass of . The discovery showed an exceptionally strong peak, with 20-sigma significance. It is hypothesized that studying the behavior of the double-charm tetraquark may play a part in explaining the behavior of the

strong force The strong interaction or strong force is a fundamental interaction that confines quarks into proton, neutron, and other hadron particles. The strong interaction also binds neutrons and protons to create atomic nuclei, where it is called the n ...

. Following the discovery of the T, researchers now plan experiments to find its double-

beauty Beauty is commonly described as a feature of objects that makes these objects pleasurable to perceive. Such objects include landscapes, sunsets, humans and works of art. Beauty, together with art and taste, is the main subject of aesthetics, o ...

counterpart T. This tetraquark has been found to have a longer lifespan than most known exotic-matter particles.

References

External links

Observation and study of the doubly charmed T_cc⁺ tetraquark at LHCb
presentation by Ivan Polyaokov at CERN, 2021-09-14 Hadrons Mesons Large Hadron Collider 2021 in science Subatomic particles with spin 1 {{particle-stub