High-energy ‘ghost’ neutrinos detected for the first time in the world’s largest particle accelerator

For the first time in history, physicists have created high-energy “ghost particles” inside the world’s largest particle accelerator.

These discoveries could help unlock the secrets of how stars transform into supernovas.

CC microscopic particles, called neutrinos, discovered by FASER neutrino detector In Large Hadron Collider (LHC) – the world’s largest particle accelerator, located at the European Organization for Nuclear Research (CERN), near Geneva, Switzerland.

Neutrinos get their spectral nickname because their electrical charge is non-existent and their near-zero mass means they have difficulty interacting with other types of matter.

Illustration of three neutrinos

Illustration of three neutrinos, ghostly particles that barely interact with other forms of matter.

True to their spooky nickname, neutrinos pass through ordinary matter at close to the speed of light. Physicists presented their results at the 57th Rencontres de Moriond Electroweak Interactives and Unified Theories conference in La Thuile, Italy, on March 19.

“We discovered neutrinos from a completely new source: particle colliders – where two particle beams collide at extremely high energies, “ Jonathan Feng, a physicist at the University of California, Irvine and co-spokesperson for the FASER collaboration, said in a statement.

Every second, around 100 billion neutrinos pass through every square centimeter of your body. Extremely small particles are everywhere. They are created in the nuclear fires of stars, in giant supernova explosions, by cosmic rays and radioactive decay, and in particle accelerators and nuclear reactors on Earth.

In fact, neutrinos, first discovered emerging from a nuclear reactor in 1956, are second only to photons as the most abundant subatomic particles in the universe.

Yet despite their ubiquity, the uncharged and nearly massless particles’ minimal interactions with other matter make them very difficult to detect.

Despite this, many famous neutrino detection experiments, such as Japan’s Super-Kamiokande detector, Fermilab’s MiniBooNE, and the IceCube detector in Antarctica, have successfully detected neutrinos produced by the Sun.

Neutrinos from supernova explosions

However, the neutrinos that reach us from the Sun represent only a small fraction of the ghost particles that exist. At the other end of the energy spectrum are high-energy neutrinos created during giant supernova explosions and during particle showers when particles from deep space plunge into Earth’s atmosphere. These high-energy ghosts still remain a mystery to scientists today.

Jamie Boyd, particle physicist at CERN and FASSR co-spokesperson, said: “These very high energy neutrinos present in the LHC are important for understanding some truly exciting observations in particle astrophysics. The new findings could help explain how stars burn and explode, as well as how the interactions of high-energy neutrinos trigger the production of other particles in space. »

Device to “capture” neutrinos

To capture the ghost of atomic particles, physicists built a particle detector: dense metal plates of lead and tungsten sandwich several layers of light-detecting liquid called emulsions. When high-energy proton beams collide inside the LHC, they create a shower of by-product particles, a small portion of which are neutrinos, which enter the LHC.

By “develop” By analyzing this film emulsion and analyzing the particle tracks, the physicists discovered that some of these tracks were created by jets of particles generated by neutrinos passing through the plates.

The six neutrinos detected by this experiment were first identified in 2021. Yet it took physicists two years to collect enough data to confirm their reality. They now hope to discover more and believe they could be used to probe space environments where high-energy ghost particles are created.

Article source: Tien Phong