Scientists associated with CERN's Large Hadron Collider have created quark-gluon plasma, a matter thought to exist at the birth of the universe, using a shockingly small amount of particles.
The plasma was first discovered using colliding protons with lead nuclei existing in high energy within the supercollider's Compact Muon Solenoid detector, and the researchers have dubbed it "the littlest liquid," the University of Kansas reported.
"Before the CMS experimental results, it had been thought the medium created in a proton on lead collisions would be too small to create a quark-gluon plasma," said Quan Wang, a KU postdoctoral researcher working with the team at CERN, the European Organization for Nuclear Research. "Indeed, these collisions were being studied as a reference for collisions of two lead nuclei to explore the non-quark-gluon-plasma aspects of the collisions. The analysis presented in this paper indicates, contrary to expectations, a quark-gluon plasma can be created in very asymmetric proton on lead collisions."
The researchers believe these stunning new findings could provide key insights into high-energy physics. The study is the first to reveal that multiple particles are related to one another in proton-lead collisions.
"This is probably the first evidence that the smallest droplet of quark gluon plasma is produced in proton-lead collisions," said Yen-Jie Lee, assistant professor of physics at MIT and co-convener of the CMS heavy-ion physics group.
The liquid was described as an extremely hot and dense state of matter of unbound quarks and gluons that cannot be contained within individual nucleons.
"It's believed to correspond to the state of the universe shortly after the Big Bang," Wang said. "The interaction between partons -- quarks and gluons -- within the quark-gluon plasma is strong, which distinguishes the quark-gluon plasma from a gaseous state where one expects little interaction among the constituent particles."
Most studies on high-energy particle physics focus on the detection of subatomic particles, but this new research looks at the behavior of a volume of these types of particles. The researchers hope the findings will give them a glimpse into the conditions present during the Big Bang.
"While we believe the state of the universe about a microsecond after the Big Bang consisted of a quark-gluon plasma, there is still much that we don't fully understand about the properties of quark-gluon plasma," Wang said. "One of the biggest surprises of the earlier measurements at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory was the fluid-like behavior of the quark-gluon plasma. Being able to form a quark-gluon plasma in proton-lead collisions helps us to better define the conditions needed for its existence."
The findings were published in a recent edition of the journal APS Physics.
