Researchers have made a groundbreaking discovery in the study of high-energy collisions, shedding new light on the enigmatic quark-gluon plasma (QGP) and its crucial role in understanding the early moments of the universe after the Big Bang.
Hunting the Core of the Quark-Gluon Plasma
Physicists have discovered a puzzling new piece of the puzzle in the world of high-energy partons — hefty particles that shoot out of protons and into whatever crashes into them, such as lead nuclei at Brookhaven National Laboratory’s Relativistic Heavy Ion Collider (RHIC) or CERN’s Large Hadron Collider. This finding is a key step in unearthing of the secrets behind the beginning’s quantum universe.
The QGP is a new form of matter, unlike any other that we are familiar with in our everyday world, and can only be produced during high-energy collisions due to the high energy and density of the collision to produce such a hot, compressed, and highly energetic state. Jet quenching refers to the loss of energy that partons experience as they traverse this medium. The rate at which energy is radiated is one of the most sensitive observables to understand properties and dynamics of QGP, a hot soup believed to have existed in the very first moments after the Big Bang.
The Mysteries of Parton Energy Loss Revealed
It was found in the study that when the medium temperature increases, so does a key quantity used to measure how much energy is lost by an outgoing quark passing through the hot QGP — the jet transport coefficient. We found this measurement to be consistent with a dramatic increase in the elliptic flow parameter (v2(pT)) for high-pT hadrons, which was taken as evidence of significant jet quenching in high-energy collisions.
The researchers fitted their models to the experimental data using a next-to-leading-order perturbative QCD parton model on the data from the Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC), and discovered this new connection between both the linearity of jet transport coefficient with respect to temperature. This new result is interpreted as an indication that more energy loss is induced on partons through the QGP fireball when it occurs at the critical temperature where the transition from hadrons to quarks and gluons takes place, which also enhances high-energy collisions with large azimuthal pressures.
Conclusion
This landmark study has dramatically increased our knowledge of the quark-gluon plasma and its significance for the evolving universe. The new finding provides a better way to describe the interaction between partons, also known as quarks and gluons, in an ultrahot plasma by uncovering details about how jet transport coefficient depends on temperature. Acting as a door stop for further investigations to the basic building blocks of our universe and profound insights into properties of matter under physically extreme conditions.
