Scientists have finally detected neutrinos in the particle collider: ScienceAlert

Finally, the ghost is already in the machine: For the first time, scientists have created neutrinos in a particle collider.

These plentiful and mysterious subatomic particles are so removed from the rest of matter that they glide through them like spectra, making them known as “ghost particles.”

The researchers say this work marks the first direct observation of the collider’s neutrinos and will help us understand how these particles form, what their properties are, and their role in the evolution of the universe.

Results achieved using the FASERnu detector at the Large Hadron Collider, have been shown At the 57th Rencontres de Moriond Conference on Electroweak Interactions and Unified Theories in Italy.

“We’ve discovered neutrinos from a completely new source – particle colliders – where you have two beams of particles colliding together at extremely high energy,” says particle physicist Jonathan Feng from the University of California, Irvine.

Neutrinos are among the most abundant subatomic particles in the universe, second only to photons. But they have no electric charge, their mass is close to zero, and they hardly interact with other particles they encounter. Hundreds of billions of neutrinos are streaming through your body right now.

Neutrinos are produced in energetic conditions, such as nuclear fusion that occurs inside stars, or supernova explosions. And while we may not notice them on a daily basis, physicists believe that their mass – however slight – may affect the gravity of the universe (although neutrinos have been largely Bounces as dark matter).

Although their interaction with matter is negligible, it is not entirely non-existent; Every now and then, a cosmic neutrino collides with another particle, resulting in a very faint burst of light.

Underground detectors, isolated from other sources of radiation, can detect these explosions. ice Cube in Antarctica, Super Kamiokande in Japan and mini bun Fermilab in Illinois has three such reagents.

However, physicists have long sought to produce neutrinos in particle colliders because the high energies used have not been as well studied as the lower-energy neutrinos.

“They can tell us about deep space in ways we can’t otherwise learn,” says particle physicist Jamie Boyd of CERN. “These high-energy neutrinos at the LHC are important for understanding really exciting observations in particle astrophysics.”

FASERnu is a file emulsion detector It consists of alternating millimeter-thick tungsten plates with layers of emulsion film. Tungsten was chosen because of its high density, which increases the likelihood of neutrino interactions; The detector consists of 730 emulsion films with a total mass of tungsten of about 1 ton.

During particle experiments at the LHC, neutrinos can collide with the nuclei of tungsten sheets, producing particles that leave traces in emulsion layers, much like the way ionizing radiation makes tracks in cloud room.

Like photographic films, these panels need to be developed before physicists can analyze particle trajectories to see what produced them.

Six candidate neutrinos have been identified and published again in 2021. Now, the researchers have confirmed their discovery, using data from the third round of the upgraded LHC that began last year, with a significance level of 16 sigma.

This means that the probability of producing the signals by random chance is so low as to be nil; The significance level of 5 sigma is sufficient to qualify as a discovery in particle physics.

The FASER team is still hard at work analyzing the data collected by the detector, and it seems likely that more neutrino detections will follow. The LHC’s third run is expected to continue Until 2026Continuous data collection and analysis.

In 2021, physicist David Casper of the University of California, Irvine, predicts that the race will produce about 10,000 neutrino interactions, which means we’ve barely scratched the surface of what FASERnu has to offer.

“Neutrinos are the only known particles that much larger experiments at the Large Hadron Collider cannot detect directly.” He saysSo the successful observation of FASER means that the full physics potential of the collider is finally being exploited.

The results of the team Presented at the 57th Congress Rencontres de Moriond Electroweak Interactions and Unified Theories.