New form of 'spooky' matter found?
Recent experiments at the Large Hadron Collider (LHC) at CERN in Switzerland —the same famous facility that discovered the elusive Higgs boson earlier this year— may have discovered a new type of matter in which particles seemingly interact without any direct connection with each other: "color-glass condensate".
The LHC routinely smashes particles together in high-speed collisions, which promptly breaks the particles up into their constituent sub-particles. Normally, these "shrapnel" fly away in all directions, much like the debris in a car crash. But scientists observing the collision using the LHC's Compact Muon Solenoid (CMS) found some pairs of particles that flew away from each other in an orderly, correlated manner —almost as if they knew what the other was doing, even though they were not directly connected to each other.
“Somehow they fly at the same direction even though it's not clear how they can communicate their direction with one another. That has surprised many people, including us,” Massachusetts Institute of Technology (MIT) physics professor Gunther Roland told MIT News. His team lead the analysis of the collision data, with Wei Li, assistant professor at Rice University.
This kind of particle behavior had previously been observed in collisions between larger particles, under conditions similar to those that existed in the first few millionths of a second after the Big Bang.
Two years ago, in 2010, Roland and other MIT physicists found that smashing heavy ions of lead, gold, and copper together caused a wave of "quark gluon plasma" that caused some of the fragments of the ions to be pushed in the same direction.
A similar phenomenon might be happening in collisions between protons and proton-lead collisions, as demonstrated at CERN, in a liquid-like wave of smaller particles called gluons.
"It has been theorized that proton-proton collisions may produce a liquid-like wave of gluons, known as color-glass condensate. This dense swarm of gluons may also produce the unusual collision pattern seen in proton-lead collisions," Brookhaven National Laboratory senior scientist Raju Venugopalan told MIT News.
Venugopalan and his former student, Kevin Dusling, theorized the existence of color glass condensate before proton-proton collisions manifested correlated particle direction, MIT News reported.
Venugopalan said that this correlation may be due to quantum mechanics: "This 'quantum entanglement' explains how the particles that fly away from the collision can share information such as direction of flight path."
The correlation is “a very tiny effect, but it’s pointing to something very fundamental about how quarks and gluons are arranged spatially within a proton,” he added.
Quantum entanglement happens when particles that were initially connected continue to behave as if they are still interacting with each other even after they have been separated.
The phenomenon was so startling that Albert Einstein famously dubbed it "spooky action at a distance."
The CMS team ran proton-lead collisions to get better control data, but were surprised the experiments produced unexpected results.
“It was supposed to be sort of a reference run —a run in which you can study background effects and then subtract them from the effects that you see in lead-lead collisions," said Roland.
MIT News reported that the run lasted for four hours, but the CMS team intends to conduct several weeks of lead-proton collisions in January to help "narrow down the possible explanations determine if the effects seen in proton-proton, lead-proton and lead-lead collisions are related."
However, Popular Science Magazine reported that the proton-lead collisions suggest "some newly understood behavior at the tiniest levels."
"Refining our understanding of how quarks and gluons behave within protons will improve our understanding of the building blocks of all matter, and how it behaved right after the Big Bang," Popular Science Magazine noted. — TJD, GMA News