Scientists at the Relativistic Heavy Ion Collider (RHIC) at the US Department of Energy’s Brookhaven National Laboratory have made a groundbreaking discovery regarding magnetic fields in particle collisions. The analysis of particle interactions at RHIC has revealed record-breaking magnetic fields imprinted on the material shed by crashing together heavy ions. This discovery provides valuable insights into the forces at work deep inside atoms and helps physicists better understand the construction of matter.
The study focused on measuring the shrapnel of quark and gluon particles that are set free during off-center collisions. Quarks are fundamental particles that exist fleetingly in quantum blizzards, and their interactions are governed by gluon particles. These interactions bind quarks and antiquarks together to form protons and neutrons, which are the building blocks of all atoms.
One of the challenges in studying quarks and antiquarks is the short lifespan of the electromagnetic field within a fog of exposed quarks and gluons. It rapidly succumbs to the flow of competitive currents, making it difficult to observe. However, physicists theorized that collisions between heavy nuclei not perfectly centered could generate a powerful magnetic field.
When heavy nuclei collide off-center, the protons within them are sent spiraling in a charged swirl, creating a strong magnetic field. Physicists predicted that these collisions could generate a magnetic field as strong as 10^18 gauss, making it potentially the strongest magnetic field in the universe. For comparison, this is 10,000 times stronger than the most powerful magnetar and 10 quadrillion times stronger than a typical fridge magnet.
Although these bursts of magnetism last for an incredibly short duration (a mere ten millionths of a billionth of a billionth of a second), their presence can still be felt by the charged quarks released during the collision. By analyzing the remnants of gold-gold collisions and collisions of ruthenium and zirconium, researchers were able to identify the paths taken by particles, indicating the presence of the magnetic field.
This discovery also provided valuable information about the quark-gluon plasma’s electrical conductivity. By measuring the distribution of particles, scientists could infer the value of the conductivity, which had never been measured before.
“This is the first measurement of how the magnetic field interacts with the quark-gluon plasma (QGP),” says Diyu Shen, a physicist at the Solenoidal Tracker at RHIC (STAR) collaboration at the DOE.
The findings of this research were published in Physical Review X, marking a significant milestone in our understanding of magnetic fields and particle interactions. The ability to study these record-breaking magnetic fields opens up new avenues for exploring the fundamental properties of matter and the forces that shape our universe.
