F 1.12

(image via Interactions.org)

Physicists unlock mystery of subatomic particle

“European researchers observe for the first time a transformation in neutrinos, evidence that they have mass. It’s an important step in understanding the universe’s dark matter.

For the first time, physicists have confirmed that certain subatomic particles have mass and that they could account for a large proportion of matter in the universe, the so-called dark matter that astrophysicists know is there but that cannot be observed by conventional means.

The finding concerns the behavior of neutrinos, ghost-like particles that travel at the speed of light. In the new experiment, physicists captured a muon neutrino in the process of transforming into a tau neutrino.

Neutrinos interact with matter so weakly that they can travel through the entire Earth with the ease of a light beam traveling through a windowpane. They have no electrical charge — hence the name, meaning “little neutral one.”

The discovery comes from the infinitely patient and creative researchers in an experiment known as OPERA, for Oscillation Project with Emulsion-tRacking Apparatus.

The project’s source of neutrinos is a proton accelerator at CERN in Geneva that slams protons into a graphite target, producing particles called pions and kaons that quickly decay into muon neutrinos.

Because the neutrino beam that is created is not affected by electrical or magnetic fields, the proton accelerator must be pointed directly at detectors in the laboratory under Gran Sasso mountain 453 miles away in central Italy, between the towns of L’Aquila and Teramo. When neutrinos are produced, they continue in the same direction of the proton beam, arriving at Gran Sasso in 2.4 milliseconds. [story via the LA Times]”