What are neutrinos? - Space.com

Their tendency not to interact very often with other particles makes detecting neutrinos very difficult, but it does not mean that they never interact — the probability that any given neutrino will interact with another particle is just very small. .

At KATRIN (opens in new tab), the Karlsruhe Tritium Neutrino Experiment in Germany, scientists were able to measure the upper limit of the neutrino mass to be 0.8 electronvolts, or eV.

Hence this is how neutrinos are produced; the KATRIN experiment, for instance, measured the mass of neutrinos that resulted from the decay of tritium isotopes.

Their neutrino detector consisted of scintillating fluid and photomultiplier tubes (opens in new tab) and didn't detect the neutrino directly.

The first 'natural' neutrino to be detected (opens in new tab) was found in 1965 at an experiment deep underground at the East Rand goldmine in South Africa, but it wasn't until the famous Homestake Mine detector was built that neutrino physics really came of age.

Physicists John Bahcall and Ray Davis, Jr built an experiment deep in the mine (opens in new tab) to detect neutrinos coming from the core of the sun, where nuclear fusion reactions turn hydrogen into helium.

This is called neutrino oscillation (opens in new tab), but it only works if neutrinos have mass, and until recently they were thought to be mass-less.

However, two to three hours before the visible light of the supernova reached us, a burst of neutrinos (opens in new tab) was detected coming from the dying star.

Only a handful of neutrinos were detected at each detector around the world, but given how weakly neutrinos interact, the two-dozen detections was well above the background level and indicated a huge burst of neutrinos that had been produced as the core of the star collapsed.

It was the first time that neutrinos had been detected coming from a supernova, and confirmed various theories about how massive stars end their lives.

Since then, neutrinos have also been detected coming from violent events around active supermassive black holes, such as those found in quasars and blazars.

Even with countless neutrinos filling every nook and cranny of the universe, at a maximum of 0.8eV, the three known flavors of neutrino — electron, muon and tau — are still not enough to account for all the dark matter.

An experiment at the Liquid Scintillator Neutrino Detector at Los Alamos National Laboratory found that more muon antineutrinos were oscillating into electron antineutrinos (opens in new tab) than theory predicted.

It would only interact via gravity, and would not interact with the other forces of nature at all, unlike the other three flavors of neutrino that interact with the weak force.

If sterile neutrinos are at the upper end of the estimated mass range, they could explain at least some of the mysterious dark matter.

The leading present-day neutrino detector is the IceCube Observatory.

The digital optical modules then detect the flash of Cherenkov radiation, recording the presence of a neutrino interaction.

The latest observing run of the Large Hadron Collider is also set up to detect neutrinos.

Previously the LHC has not had the capability to detect neutrinos created in its particle collisions, but for its latest observing run two new neutrino-detecting instruments — the Forward Search Experiment (FASER) (opens in new tab) and the Scattering and Neutrino Detector (opens in new tab) — have been introduced, and among other things they will be searching for evidence of sterile neutrinos.

Looking further into the future, scientists are hoping to build the Pacific Ocean Neutrino Experiment (opens in new tab) (P-ONE), which would be a giant neutrino detector at least two miles deep, with strands of photodetectors kept afloat across several square miles, and which would detect Cherenkov light like IceCube.

Find out if neutrinos are the reason matter exists (opens in new tab) with the informative website all things neutrino.

Retrieved September 21, 2022, from https://www.nature.com/articles/d41586-021-01318-y.

Retrieved September 21, 2022, from https://www.nobelprize.org/prizes/themes/solving-the-mystery-of-the-missing-neutrinos/.

Retrieved September 21, 2022, from https://www.nature.com/articles/s41567-019-0435-6.

Retrieved September 21, 2022, from https://neutrinos.fnal.gov/sources/big-bang-neutrinos/.

Retrieved September 21, 2022, from https://ui.adsabs.harvard.edu/abs/1987ApJ...318L..63B/abstract.

Retrieved September 21, 2022, from https://faser.web.cern.ch/.

Retrieved September 21, 2022, from https://www.nationalacademies.org/our-work/decadal-survey-on-astronomy-and-astrophysics-2020-astro2020.

Retrieved September 21, 2022, from https://icecube.wisc.edu/news/press-releases/2017/11/first-look-at-how-earth-stops-high-energy-neutrinos-in-their-tracks/.

Retrieved September 21, 2022, from https://www.iaea.org/newscenter/news/what-is-cherenkov-radiation.

Retrieved September 21, 2022, from https://www.aps.org/publications/apsnews/201107/physicshistory.cfm.

Retrieved September 21, 2022, from https://www.katrin.kit.edu/.

Retrieved September 21, 2022, from https://www.symmetrymagazine.org/article/the-search-for-the-sterile-neutrino.

Retrieved September 21, 2022, from https://adsabs.harvard.edu/full/1969tsra.conf..305R.

Retrieved September 21, 2022, from https://neutrinos.fnal.gov/types/sterile-neutrinos/

Retrieved September 21, 2022, from https://sno.phy.queensu.ca/

Retrieved September 21, 2022, from https://www.pacific-neutrino.org/

Retrieved September 21, 2022, from https://sci.esa.int/web/euclid/-/what-are-baryonic-acoustic-oscillations-