Double-charm tetraquark

The double-charm tetraquark (T$3,868 MeV/c2$, cc$1.35 s$$+ cc$) is a type of long-lived tetraquark that was discovered in 2021 in the LHCb experiment conducted at the Large Hadron Collider. It contains four quarks: two charm quarks, an anti-up and an anti-down quark.

It has a theoretical computed mass of $\overline{u}$. 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. Following the discovery of the T$\overline{d}$, researchers now plan experiments to find its double-beauty counterpart T$3,868 MeV/c2$. This tetraquark has been found to have a longer lifespan than most known exotic-matter particles.