Concept image of an atom and electrons.
(photo credit: INGIMAGE)
Researchers at Tel Aviv University and the University of Chicago have shown that a huge amount of energy – 10 times that of nuclear fusion – can be produced by melting elementary particles called quarks. The study, considered to be a “breakthrough,” was just published in the journal Nature along with a special editorial on the Israeli findings.
The research was carried out by TAU physics Prof. Marek Karliner, in cooperation with Prof. Jonathan L. Rosner of the University of Chicago. The researchers calculated the amount of energy that could be generated by the fusion of different types of quarks and found it could be 10-fold greater than the energy generated by nuclear fusion.
Quarks are the most basic building blocks of matter in the universe. Most of the matter we see around us is made from protons and neutrons, which are composed of quarks. They have the unusual characteristic of having a fractional electric charge, unlike the proton and electron, which have charges of +1 and -1. There are six types of quarks, but physicists usually refer to them in terms of three pairs: up/down, charm/strange, and top/bottom. Quarks join together to form composite particles called hadrons. The most stable of these are protons and neutrons, the components of atomic nuclei.
“Nuclear fusion is a familiar process in which atomic nuclei merge and emit energy,” explained Karliner of TAU’s Sackler Faculty of Exact Sciences. “The process happens naturally in the stars of the universe, like our sun. Man has learned to use it to make hydrogen bombs. Attempts are being made to use this process to produce nuclear fusion power, but these experiments have not yet matured,” he added.
Physicists have wondered whether fusion is also possible from the smaller particles called quarks. A few months ago, experimental physicists at the CERN particle accelerator near Geneva discovered a new type of particle called a baryon, which contains two heavy quarks of the kind called a “charm” and a “light quark.” The new particle is exactly the same as that predicted by Karliner and Rosner, who published their theory in the scientific press three years ago. The experimental discovery, which confirmed the theoretical prediction, has sparked many reactions in the world scientific community and much space has been devoted to it in the last few days in The New York Times.
Given the mass of the particles involved before and after melting, the amount of energy emitted can be calculated precisely by Einstein’s famous E = mc2 formula, they said. The calculation showed that the amount of energy emitted between two baryons with a “charm” quark is 12 million electron volts, similar to that emitted by nuclear fusion between two heavy isotopes of hydrogen.
The precise measurement of the particle of the two “charm” quarks allows them to simulate for the first time a process of fusion at the quark level and calculate its results.
“We calculated what happens when the type of baryon discovered in the accelerator was created by the fusion of two baryons each containing one ‘charm’ quark,” Karliner concluded. “In other words, more efficient packaging of quarks in baryons releases energy, just as efficient packaging of protons and neutrons releases energy in regular nuclear fusion.”
“It is important to emphasize that although our findings have aroused considerable interest in theory, they have no practical application,” said Karliner. “A nuclear fusion that occurs in a reactor or a hydrogen bomb is a chain reaction in a mass of particles, creating a huge amount of energy. This is not possible by melting heavy quarks, simply because the raw material cannot be accumulated in the melting process. If we thought for a moment that our discovery had some dangerous application, we would not publish it.”