Click to enlarge — Ice Cube Collaboration
From where do these neutrinos come? The IceCube Neutrino Observatory near the South Pole of the Earth has begun to detect nearly invisible particles of very high energy. Although these rarely-interacting neutrinos pass through much of the Earth just before being detected, where they started remains a mystery. Pictured here is IceCube’s Antarctic lab accompanied by a cartoon depicting long strands of detectors frozen into the crystal clear ice below. Candidate origins for these cosmic neutrinos include the violent surroundings of supermassive black holes at the centers of distant galaxies, and tremendous stellar explosions culminating in supernovas and gamma ray bursts far across the universe. As IceCube detects increasingly more high energy neutrinos, correlations with known objects may resolve this cosmic conundrum — or we may never know.
Ursarodinia kicks off this week’s PAWS and CLAWS newsletter featuring the Ice Cube Observatory. Which reminded me that I’ve had the article below sitting in the hopper for a month. It’s very interesting to me – as is her find on the same topic. Time to offer up both together.
NOvA is on a quest to learn more about the abundant yet mysterious particles called neutrinos, which flit through ordinary matter as though it weren’t there. The first NOvA results, released…at the American Physical Society’s Division of Particles and Fields conference in Ann Arbor, Michigan, verify that the experiment’s massive particle detector — 50 feet tall, 50 feet wide and 200 feet long — is sitting in the sweet spot and detecting neutrinos fired from 500 miles away. Scientists have sorted through millions of cosmic ray strikes and zeroed in on neutrino interactions…
The neutrino beam generated at Fermilab passes through an underground near detector, which measures the beam’s neutrino composition before it leaves the Fermilab site. The particles then travel more than 500 miles straight through Earth, no tunnel required, oscillating (or changing types) along the way. About once per second, Fermilab’s accelerator sends trillions of neutrinos to Minnesota, but the elusive neutrinos interact so rarely that only a few will register at the far detector.
When a neutrino bumps into an atom in the NOvA detector, it releases a signature trail of particles and light depending on which type it is: an electron, muon or tau neutrino. The beam originating at Fermilab is made almost entirely of one type — muon neutrinos — and scientists can measure how many of those muon neutrinos disappear over their journey and reappear as electron neutrinos.
If oscillations did not occur, experimenters predicted they would see 201 muon neutrinos arrive at the NOvA far detector in the data collected; instead, they saw a mere 33, proof that the muon neutrinos were disappearing as they transformed into the two other flavors. Similarly, if oscillations did not occur, scientists expected to see only one electron neutrino appearance (due to background interactions). But the collaboration saw six such events, evidence that some of the missing muon neutrinos had turned into electron neutrinos…
Neutrinos are the most abundant massive particle in the universe but are still poorly understood. While researchers know that neutrinos come in three types, they don’t know which is the heaviest and which is the lightest. Figuring out this ordering — one of the goals of the NOvA experiment — would be a great litmus test for theories about how the neutrino gets its mass. While the famed Higgs boson helps explain how some particles obtain their masses, scientists don’t know yet how it is connected to neutrinos, if at all. The measurement of the neutrino mass hierarchy is also crucial information for neutrino experiments trying to see if the neutrino is its own antiparticle.
You know, I figure I’m good for another 10 or 20 years. I guess I could consider starting out, once again, on a new career. And that would be computational analysis in one or another scientific field – or multiple fields. My wife is already expert enough in some of the computing fields I’ve managed to avoid. We would be a helluva pair. But, we’re both happy at how we live here at Lot 4.
We get a fair piece of individual intellectual inquiry started through this blog and others – and more. It’s just a tempting thought and I figured I’d note it.