CMS detector.
Photo courtesy CERN.
(September 4, 2015) Researchers
at the University of Kansas working with an international team at the Large
Hadron Collider have produced quark-gluon plasma — a state of matter thought to
have existed right at the birth of the universe — with fewer particles than
previously thought possible.
The material was discovered by colliding protons with lead
nuclei at high energy inside the supercollider’s Compact Muon Solenoid
detector. Physicists have dubbed the resulting plasma the “littlest liquid.”
“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.
“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,” Wang said. “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 unexpected discovery was said by
senior scientists associated with the CMS detector to shed new light on
high-energy physics.