QUARKS- BUILDING BLOCKS OF UNIVERSE

Why in news? :The Large Hadron Collider beauty (LHCb) experiment studying a type of particle called the “beauty quark”, or “b quark”, has observed three never-before-seen particles i.e. “exotic” additions — a new kind of “penta-quark” and the first-ever pair of “tetra-quarks” — to the growing list of new hadrons.

What are quarks? : Elementary particles that come in six “flavours”: up, down, charm, strange, top, and bottom. They usually combine together in groups of twos and threes to form hadrons such as the protons and neutrons that make up atomic nuclei.

They can also combine into four-quark and five-quark particles, called tetraquarks and pentaquarks. These exotic hadrons were predicted by theorists about six decades ago but they have been observed by LHCb and other experiments only in the past 20 years.

What are tetra and penta quarks? :

Most exotic hadrons discovered in the past two decades are tetraquarks or pentaquarks containing a charm quark and a charm antiquark — with the remaining two or three quarks being an up, down or strange quark or their antiquarks.

LHCb experiment discovered an exotic tetraquark made up of two charm quarks and two charm antiquarks, and two “open-charm” tetraquarks consisting of a charm antiquark, an up quark, a down quark and a strange antiquark.

Open charm means that the particle contains a charm quark without an equivalent.

What is LHCb Experiment? :The Large Hadron Collider beauty (LHCb) experiment — which is investigating the slight differences between matter and antimatter by studying a type of particle called the “beauty quark”, or “b quark”. This experiment is conducted by CERN. The LHC, re-ignited after three years was cranked up to unprecedented levels of energy and has begun smashing together protons at almost the speed of light, which could throw up “new” physics beyond the Standard Model.

What is CERN? : Conseil Européen pour la Recherche Nucléaire — is the original name of the European Organisation for Nuclear Research, which runs the particle accelerator complex that houses the LHC, the world’s largest and most complex collider.