Aug 3, 2017

'Ghost particles' detected interacting with atom's nucleus for first time

Jean Lachat / University of Chicago

Neutrinos are some of the most common particles in the universe, but they're also some of the most mysterious. They have (almost) no mass and no charge, and can pass through solid objects (and entire planets) like we pass through air. But scientists at Duke University have successfully detected these 'ghost particles' doing something no one has seen before: scattering off the nucleus of an atom.

Why it matters: Currently, scientists study neutrinos by measuring the energy produced when they interact with a proton or neutron — a very rare event. Now that scientists know they can detect neutrinos scattering off a nucleus, they might be able to use them to detect supernovas, or use a similar technique to detect dark matter scattering off of nuclei, reports Science News.

Physicists say understanding neutrinos is crucial to our understanding of the universe. They're produced by nuclear fusion and radioactive decay. Some scientists think neutrinos might be a part of why the universe is made up of matter and not antimatter.

Not quite a game changer: Forty years ago, researchers hypothesized that neutrinos would scatter a certain way if they interacted with a nucleus, according to the standard model of physics. In this experiment, the neutrino scattered exactly as predicted (and the standard model is safe... for now.)

Handheld physics lab: Not only are neutrinos really, really hard to observe, most of the equipment currently used to detect them is really, really big and expensive. For example, the proposed India-based Neutrino Observatory requires a 50,000 ton calorimeter. But the researchers in this experiment used a detector about the same size as a champagne bottle.

Go deeper

Minneapolis unrest as hundreds protest death of George Floyd

Tear gas is fired as police clash with protesters demonstrating against the death of George Floyd outside the 3rd Precinct Police Precinct in Minneapolis, Minnesota, on Tuesday. Photo: Stephen Maturen/Getty Images

Minneapolis police used tear gas during clashes with protesters demanding justice Tuesday night for George Floyd, an African American who died in police custody, according to multiple news reports.

Driving the news: The FBI is investigating Floyd's death after video emerged of a Minneapolis police officer kneeling on his neck for several minutes, ignoring protests that he couldn't breathe. Hundreds of protesters attended the demonstration at the intersection where Floyd died, per the Guardian.

U.S. coronavirus updates

Data: The Center for Systems Science and Engineering at Johns Hopkins; Map: Andrew Witherspoon/Axios. This graphic includes "probable deaths" that New York City began reporting on April 14.

More than 62,300 U.S. health care workers have tested positive for the novel coronavirus and at least 291 have died from the virus, the Centers for Disease Control and Prevention reported on Tuesday. COVID-19 had infected about 9,300 health professionals when the CDC gave its last update on April 17.

By the numbers: More than 98,900 people have died from COVID-19 and over 1.6 million have tested positive in the U.S. Over 384,900 Americans have recovered and more than 14.9 million tests have been conducted.

Coronavirus dashboard

Illustration: Aïda Amer/Axios

  1. Global: Total confirmed cases as of 11:00 p.m. ET: 5,589,626 — Total deaths: 350,453 — Total recoveries — 2,286,956Map.
  2. U.S.: Total confirmed cases as of 11:00 p.m. ET: 1,680,913 — Total deaths: 98,913 — Total recoveries: 384,902 — Total tested: 14,907,041Map.
  3. Federal response: DOJ investigates meatpacking industry over soaring beef pricesMike Pence's press secretary returns to work.
  4. Congress: House Republicans to sue Nancy Pelosi in effort to block proxy voting.
  5. Business: How the new workplace could leave parents behind.
  6. Tech: Twitter fact-checks Trump's tweets about mail-in voting for first timeGoogle to open offices July 6 for 10% of workers.
  7. Public health: Coronavirus antibodies could give "short-term immunity," CDC says, but more data is neededCDC releases guidance on when you can be around others after contracting the virus.
  8. What should I do? When you can be around others after contracting the coronavirus — Traveling, asthma, dishes, disinfectants and being contagiousMasks, lending books and self-isolatingExercise, laundry, what counts as soap — Pets, moving and personal healthAnswers about the virus from Axios expertsWhat to know about social distancingHow to minimize your risk.
  9. Other resources: CDC on how to avoid the virus, what to do if you get it, the right mask to wear.

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Updated 2 hours ago - Politics & Policy