A quark zooms through quark-gluon plasma, creating a wake in the plasma. “Studying how quark wakes bounce back and forth will give us new insights on the quark-gluon plasma’s properties,” Yen-Jie Lee says.
Image Credit: Jose-Luis Olivares, MIT
(CC BY-NC-ND 4.0)
Scientific Frontline: "At a Glance" Summary
- Main Discovery: Researchers have observed the first direct evidence that the "primordial soup" of the early universe—quark-gluon plasma—behaves as a dense, frictionless liquid rather than a gas, indicated by the formation of wakes behind speeding quarks.
- Methodology: The team utilized data from the Compact Muon Solenoid (CMS) experiment at CERN's Large Hadron Collider, where heavy lead ions were smashed together at near-light speeds to briefly recreate the primordial plasma; they then analyzed the trajectories of quark-antiquark pairs to detect specific "sloshing" or wake patterns generated as particles moved through the medium.
- Key Data: The laboratory-created plasma droplets existed for less than a quadrillionth of a second and reached temperatures of several trillion degrees Celsius, mirroring conditions just a few millionths of a second after the Big Bang.
- Significance: This confirmation resolves a longstanding debate in physics, proving that the infant universe's matter functioned as a cohesive fluid that creates ripples and swirls (similar to a boat in water) rather than a system of randomly scattering individual particles.
- Future Application: The novel technique of using quark wakes as probes will allow physicists to measure the viscosity and internal properties of quark-gluon plasma with greater precision, effectively providing a detailed "snapshot" of the universe's earliest moments.
- Branch of Science: High-Energy Particle Physics / Cosmology
- Additional Detail: The study validates the theoretical "hybrid model" which predicted that high-energy jets (quarks) would induce a hydrodynamic response in the plasma, slowing down the particles and generating a detectable wake.
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