Many particles have already been discovered at the Large Hadron Collider (LHC, France-Switzerland). Now physicists say they’ve found evidence of three never-before-seen quark combinations: a pentaquark and a pair of tetraquarks.
The list of particles discovered at(LHC, France-Switzerland) is long. There is the famous Higgs boson, of course. But also some 65 hadrons. And today, there are no less than three new objects which are added to it. A new pentaquark and the very first pair of tetraquarks ever detected.
To understand, remember that thewhat are the have a habit of associating in twos or threes. They thus form hadrons, among which the and the which are quite familiar to us. But sometimes – it is much rarer -, the quarks gather by four or even by five. To form exotic hadrons named respectively tetraquarks and pentaquarks.
A pentaquark and a pair of tetraquarks
The pentaquark discovered this time is unique in that it is the first to incorporate an s quark. Understand, aof flavor – this is how qualify the different types of quarks that exist; they know six – ” odd “ or s for « strange ». way more “classic”this pentaquark also contains a c quark – for « charm » – and its antiquark, a – pour « up » – and one – pour « down ».
The two observed tetraquarks form a pair. It is the first time thatdetect one. One of the tetraquarks in the pair is electrically doubly charged. The other is neutral. Both correspond to what researchers call a tetraquark at apparent. Understand that these tetraquarks consist of a c quark – but also of an s antiquark, an u quark and a d antiquark – without its antiquark.
And for those who are wondering, here is what Chris Parkes, the spokesperson for the LHCb collaboration, answers: “Finding new types of tetraquarks and pentaquarks, and measuring their properties will help theorists to develop a unified model of exotic hadrons – as isolated units of tightly bound quarks or as pairs of weakly bound hadrons, similar to-, but also to better understand classical hadrons. »