A group of scientists at CERN has recently discovered a brand new particle called Tcc+ with the help of Large Hadron Collider (LHCb). As per a recent presentation at the European Physical Society Conference on High Energy Physics (EPS-HEP), the particle is from a rare class called tetraquark and is the longest-lived exotic matter particle (hadron) ever discovered, and is also the first to have two heavy quarks and two light antiquarks.
Quarks are the building blocks of all matter. They can get fused and thus form hadrons and baryons, similar to the neutron and proton in standard atomic theory, along with mesons, which forms when quark pairs with its antimatter equivalents, antiquark. Several such exotic hadrons particles with generally four or five quarks rather than the traditional two or three have been discovered in past few years.
But the recent study has led to the discovery of specific exotic hadron, which can be said as super-exotic hadron. This newly discovered particle has two charm quarks, an up antiquark and a down antiquark which makes it particularly exotic. Because the pairing of quarks and antiquarks is based on their own interaction, i.e. a charm quark with a charm antiquark discovered in multiple tetraquarksin recent years.
But interestingly Tcc+ is the first particle found to have charm quarks that aren’t countered with their own antiquarks, making it a “open charm” or “double open charm”, according to researchers.
Alongside the open charm in quark content of Tcc+, the first particle belongs to a class of tetraquarks with two heavy quarks and two light antiquarks. And such particle decay by getting transformed into a pair of mesons. As per some of the theories, the mass of tetraquarks of this type is approximately equal to the sum of masses of the two mesons. Such proximity in mass makes the decay “difficult” or “slow”, resulting in a longer lifetime of the particle as observed in Tcc+, which is the longest-lived exotic hadron known.
Newly discovered Tcc+ tetraquark is very important for further research and scientists have suggested that another such particle could be even more stable. However, for now scientists continued to study the new Tcc+ particle to get more information from it.