Scientists discover new subatomic particle with four 'flavours'

Scientists discover new subatomic particle with four 'flavours'

Quarks are point-like elementary particles that typically come in packages of two or three, the most familiar of which are the proton and neutron (each is made of three quarks). Tetraquarks – four quarks together – are much rarer and are not well understood.

• There are six types, or “flavours,” of quark to choose from: up, down, strange, charm, bottom and top. Each of these also has an antimatter counterpart.
• While all other observed tetraquarks contain at least two of the same flavor, X(5568) has four different flavours – up, down, strange and bottom.
• The discovery was made by scientists – including Lancaster's Professor Iain Bertram – involved in the DZero collaboration at Fermilab, the US Government's laboratory specialising in high-energy particle physics.
• Professor Bertram said: “It is exciting to discover a new and unusual particle that will help us understand the strong interaction - one of the four known fundamental interactions in physics.”
• DZero is one of two experiments at Fermilab's Tevatron collider. Although the Tevatron was retired in 2011, the experiments continue to analyse billions of previously recorded events from its collisions.
• The tetraquark observation came as a surprise when DZero scientists first saw hints in July 2015 of the new particle, called X(5568), named for its mass – 5568 megaelectronvolts.
• Professor Bertram worked on the analysis, developing the model used to simulate the X(5568).