Indian scientists, along with their collaborators, claimed to have solved a century-old problem of defrosting matter and put a sign-post on the map of states of matter which existed in the early universe.
“The new findings give us insight into the states of matter that existed in the beginning of the universe,” said Sourendu Gupta, lead investigator of the Tata Institute of Fundamental Research (TIFR) and one of the scientists associated with the research project.
“This is the first time theoretical and experimental physicists have come together to put the sign-post on the map of states of matter described by a theory called Quantum Chromo Dynamics (QCD),” he told PTI.
Other collaborators in the project are from the US and China.
The universe was born as a hot soup of quarks, gluons and other particles. As it cooled, the soup of quarks and gluons eventually congealed into protons, neutrons and the other atomic nuclei which exist today, Gupta said.
Experiments were conducted at Relativistic Heavy-Ion Collider (RHIC) in Brookhaven Laboratory, New York, while theoretical work was done on a supercomputer at TIFR here.
During experiments, scientists marked a point called the QCD cross-over temperature. Below this temperature baryonic matter can take the form of protons and neutrons (change of states of matter), he said.
This QCD cross-over occurs at a temperature of about 2 trillion Celsius. This is by far the highest temperature at which lab experiments have probed the states of matter. The surface temperature of the sun is about 5,600 Celsius, so the QCD soup is about 350 million times hotter, Gupta said.
One of the most interesting aspects of bulk matter is that it can change state, Gupta said.
This is the beginning of a new era of quantitative studies of QCD matter where theory and experiment can improve by constantly challenging each other, the TIFR scientist said.
The scientific findings have been published in the latest issue of ‘Science’ magazine.