First Matter

The first matter that came into being right after the Big Bang may not have been quite what scientists had expected. This conclusion emerged recently from the large-scale PHENIX experiment carried out in the United States by a team of 460 physicists from 12 countries, including scientists from the Weizmann Institute.

Using an accelerator at the Brookhaven National Laboratory on Long Island, New York, the scientists may have recreated what’s believed to have been the primordial matter in the universe, known as the quark-gluon plasma. Two beams of gold ions were accelerated toward each other, causing head-on collisions. The enormous power of the collisions – about 40 trillion electron volts – turned part of the beams’ kinetic energy into various particles (a process described by Einstein’s E=mc² equation). A number of the particle detectors used in the experiment were designed and built by Prof. Itzhak Tserruya and his team in the Weizmann Institute’s Particle Physics Department.

While many of the experimental results fit in with predictions of how particles in the quark-gluon plasma should behave, others have been a surprise. In particular, scientists were amazed to discover that the plasma, created at a heat up to 150,000 times hotter than the center of the sun, behaves not like a super-hot gas, as expected, but more like a liquid! The experiment, now in its fifth year, is scheduled to run for at least five more years and is certain to yield more susprises in the future.

Prof. Itzhak Tserruya’s research is supported by the Nella and Leon Benoziyo Center for High Energy Physics and the Center for Scientific Excellence. Prof. Tserruya is the incumbent of the Samuel Sebba Professorial Chair of Pure and Applied Physics.