Large Hadron Collider team discovers new particle
The particles, known as pentaquarks, were found in a collaboration reported in a paper submitted to the journal Physical Review Letters.
“The pentaquark is not just any new particle,” said spokesperson Guy Wilkinson.
“It represents a way to aggregate quarks, namely the fundamental constituents of ordinary protons and neutrons, in a pattern that has never been observed before in over 50 years of experimental searches. Studying its properties may allow us to understand better how ordinary matter, the protons and neutrons from which we’re all made, is constituted.”
The so-called Large Hadron Collider beauty experiment, or LHCb, is an experiment set up to explore what happened after the Big Bang that allowed matter to survive and build the Universe.
The pentaquark was first predicted to exist in the 1960s. It is made of five quarks – the smallest particles that we know to exist, that in different combinations produce larger particles such as protons.
Last year, scientists at CERN found the first four-quark particle, a tetraquark.
The LHCb team says of its discovery.
Our understanding of the structure of matter was revolutionized in 1964 when American physicist, Murray Gell-Mann, proposed that a category of particles known as baryons, which includes protons and neutrons, are comprised of three fractionally charged objects called quarks, and that another category, mesons, are formed of quark-antiquark pairs. Gell-Mann was awarded the Nobel Prize in physics for this work in 1969. This quark model also allows the existence of other quark composite states, such as pentaquarks composed of four quarks and an antiquark. Until now, however, no conclusive evidence for pentaquarks had been seen.