Double-charm tetraquark


The double-charm tetraquark (T+
, ccud) is a type of long-lived tetraquark that was discovered in 2021 in the LHCb experiment conducted at the Large Hadron Collider.[1][2][3] It contains four quarks: two charm quarks, an anti-up and an anti-down quark.[2]

Double-charm tetraquark
Composition2 charm quarks
1 up antiquark
1 down antiquark

It has a theoretical computed mass of 3868±124 MeV/c2.[2] The discovery showed an exceptionally strong peak, with 20-sigma significance.[4]

It is hypothesized that studying the behavior of the double-charm tetraquark may play a part in explaining the behavior of the strong force.[5] Following the discovery of the T+
, researchers now plan experiments to find its double-beauty counterpart Tbb.[6] This tetraquark has been found to have a longer lifespan than most known exotic-matter particles.


  1. ^ "What to Know About the Newly Discovered Tetraquark at the Large Hadron Collider". Gizmodo. Retrieved 2021-09-27.
  2. ^ a b c Agaev, S. S.; Azizi, K.; Sundu, H. (2021-08-12). "Newly observed exotic doubly charmed meson T+
    ". arXiv:2108.00188 [hep-ph].
  3. ^ "Twice the charm: long-lived exotic particle discovered". CERN. Retrieved 2021-09-29.
  4. ^ "LHCb experiment spots extraordinary double charmed tetraquark". Nikhef. Retrieved 2021-09-27.
  5. ^ Wood, Charlie (2021-09-27). "'Impossible' Particle Discovery Adds Key Piece to the Strong Force Puzzle". Quanta Magazine. Retrieved 2021-09-27.
  6. ^ Turner, Ben (2021-08-05). "New 'doubly charming' particle could help unlock the secrets of how matter is built". Retrieved 2021-09-27.

External linksEdit

  • Observation and study of the doubly charmed Tcc+ tetraquark at LHCb: presentation by Ivan Polyaokov at CERN, 2021-09-14