“Littlest liquid” quark-gluon plasma produced in LHC by proton on lead collisions
Researchers have, for the first time, produced quark-gluon plasma using the Large Hadron Collider and smashing protons with lead nuclei at high energy inside the supercollider’s Compact Muon Solenoid detector.
The achievement by a team of researchers at University of Kansas and an international team of scientists at CERN is amazing because the experiment shows that quark-gluon plasma can be created in very asymmetric proton on lead collisions, which was initially thought of as being impossible because of the medium created in a proton on lead collisions would be too small to create a quark-gluon plasma.
Pegged as “littlest liquid” by the physicists behind the discovery, the unexpected discovery will help researchers garner new insights into high-energy physics.
“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. Wang performed key analysis for a paper about the experiment recently published in APS Physics.
“This is the first paper that clearly shows multiple particles are correlated to each other in proton-lead collisions, similar to what is observed in lead-lead collisions where quark gluon plasma is produced,” said Yen-Jie Lee, assistant professor of physics at MIT and co-convener of the CMS heavy-ion physics group. “This is probably the first evidence that the smallest droplet of quark gluon plasma is produced in proton-lead collisions.”
This state of matter, which is very hot and dense state of matter of unbound quarks and gluons—that is not contained within individual nucleons, is believed to correspond to the state of the universe shortly after the Big Bang.
High-energy physics at CERN has been dwelling on discovery and detection of subatomic particles like the Higgs Boson; however, the the new quark-gluon-plasma research examines behavior of a volume of such particles.
There is still very little known about quark-gluon plasma, which is said to be the state of universe about a microsecond after the Big Bang. Researchers have been surprised by the latest discovery and for the fluid-like behavior of the quark-gluon plasma and they say that being able to form a quark-gluon plasma in proton-lead collisions helps us to better define the conditions needed for its existence.
Here’s a video from Fermilab that explains the quark-gluon plasma: