The KATRIN neutrino experiment is located on the grounds of the Karlsruhe Institute of Technology in Germany. (KATRIN Photo)
Scientists from the University of Washington and other institutions around the world say they’ve reduced the upper limit for the mass of the neutrino by half.
Thanks to findings from the Karlsruhe Tritium Neutrino Experiment, or KATRIN, physicists now know to a 90% confidence level that the neutrino has a rest mass no greater than 1.1 electron volts, or 1.1 eV. The previous upper limit was 2 eV.
Nailing down the neutrino’s mass could solidify scientists’ grasp on the Standard Model, which describes the subatomic world in fine detail. It could also open a path to the mysterious realm beyond the Standard Model.
SESAME scientific director Giorgio Paolucci points out one of the magnetic devices used to accelerate electrons around the synchrotron’s ring at the facility in Jordan. (GeekWire Photo / Alan Boyle)
GeekWire’s Alan Boyle reports on a $90 million science project with a diplomatic twist in Jordan, one of the stops on this summer’s Middle East science tour.
ALLAN, Jordan — For Israeli researchers, SESAME could open up a path for finding out exactly what the frankincense mentioned in the Bible was made of.
For Arab researchers, SESAME could reveal how the awe-inspiring structures built thousands of years ago at Jordan’s Petra archaeological site were decorated.
And what’s nearly as awesome as the potential discoveries is the fact that Israelis and Arabs are working together at SESAME to make them.
On the literal level, it’s an acronym for “Synchrotron-light for Experimental Science and Applications in the Middle East.” That reflects the scientific purpose of the facility in Allan, about an hour’s drive from Amman, Jordan’s capital.
Researchers use the 436-foot-round synchrotron ring to whip up electrons and send them speeding through a magnetic obstacle course that generates brilliant flashes of light. When those light beams hit the atoms in samples of material — including bits of frankincense from the place where the Dead Sea Scrolls were found, or rock carvings borrowed from Petra — they can reveal their chemical composition in stunning detail.
“Basically, a synchrotron is a really, really big light bulb,” said Tel Aviv University biophysicist Roy Beck-Barkai, who represents Israel on SESAME’s governing council.
Scientists work in the LIGO Hanford control room. (Caltech / MIT / LIGO Lab Photo / C. Gray)
The science teams for the Laser Interferometer Gravitational-Wave Observatory, or LIGO, and Europe’s Virgo detector today laid out the details of their recent detections, including a crash between neutron stars, three black hole mergers and what may be the first observed collision of a neutron star and a black hole.
Astronomers and their fans have been talking about the detections for days, thanks to the fact that LIGO and Virgo are quickly sharing the raw results from their current observing run. But today’s statements provided the most authoritative views from researchers running the two gravitational-wave detectors.
The April 26 detection of a cosmic collision known as S190426c is the most intriguing event. The subtle signal of a far-off disturbance in the gravitational force was picked up by LIGO’s twin detectors at Hanford in Eastern Washington and at Livingston in Louisiana. The Virgo detector in Italy also detected the signal.
The signal is consistent with what might be expected if a black hole were to swallow a neutron star, roughly 1.2 billion light-years from Earth. Such an event has never been observed before.
Detector engineers Hugh Radkins (foreground) and Betsy Weaver (background) take up positions inside the vacuum system of the detector at LIGO Hanford Observatory to perform the hardware upgrades required for Advanced LIGO’s third observing run. (LIGO / Caltech / MIT Photo / Jeff Kissel)
Instead, they’ll all be bearing down for the most serious search ever conducted for signs of merging black holes, colliding neutron stars — and perhaps the first detection of a mashup involving both those exotic phenomena.
Both experiments have been upgraded significantly since their last observational runs, resulting in a combined increase of about 40 percent in sensitivity. That means even more cosmic smashups should be detected, at distances farther out. There’s also a better chance of determining precisely where cosmic collisions occur, increasing the chances of following up with other types of observations.
A diagram shows a proton-proton collision in the Large Hadron Collider’s ATLAS detector that produced a Higgs boson, which quickly decayed into two bottom quarks (bb, shown as blue cones). The collision also produced a W boson that decayed into a muon (μ) and a neutrino (ν). (ATLAS / CERN Graphic)
It’s been six years since physicists at Europe’s Large Hadron Collider announced the discovery of the Higgs boson, but they’re just now confirming what most of the mysterious subatomic particles do when they decay.
They’re transformed into bottom quarks, they announced today.
That’s not exactly a surprise: The mainstream theory of particle physics, known as the Standard Model, suggests that’s the most common course followed by the Higgs, which exists in the particle collider for only an instant before breaking down. About 60 percent of the Higgs bosons created in high-energy are thought to turn into a pair of bottom quarks, which is No. 2 on the mass scale for six “flavors” of quarks.
It took several years for researchers to nail down the evidence to a standard significance of 5-sigma — the same standard that applied to the Higgs boson’s discovery in 2012.
Experiments at Europe’s Large Hadron Collider have produced hard-to-come-by evidence of interactions between the Higgs boson and top quarks. The findings, announced today at a conference in Bologna, Italy, “give a strong indication that the Higgs boson has a key role in the large value of the top quark mass,” Karl Jakobs, spokesperson for the LHC’s ATLAS collaboration, said in a news release.
Columbia physicist Brian Greene delves into Albert Einstein’s theory of relativity in “Light Falls,” a theater piece that made its debut at the World Science Festival. (Greg Kessler Photo / World Science Festival)
After decades’ worth of mystery, it feels as if physicists are finally closing in on the nature of black holes, thanks to Nobel-winning breakthroughs like the first detections of black hole mergers at the Laser Interferometer Gravitational-wave Observatory.
But Columbia University physicist Brian Greene warns that those matter-gobbling monsters may have a few surprises in them yet.
“To watch the history of this subject unfold from a purely theoretical idea to one that now is driving observational tests is enormously exciting,” Greene told GeekWire.
Berkeley astrophysicist Saul Perlmutter discusses the implications of the universe’s accelerating expansion at the University of Washington. (GeekWire Photo / Alan Boyle)
Big data just might give astronomers a better grip on the answer to one of the biggest questions in physics: Exactly what’s behind the mysterious acceleration in the expansion rate of the universe, also known as dark energy?
The role of data analysis in resolving the mystery came to the fore on May 14 during a talk given at the DIRAC Institute’s first-ever open house on the UW campus. The speaker was none other than Berkeley astrophysicist Saul Perlmutter, who won a share of the Nobel Prize in physics in 2011 for finding the first evidence of dark energy.
Physicist Freeman Dyson’s latest book is “Maker of Patterns: An Autobiography Through Letters.” (Dan Komoda / Institute for Advanced Study, Princeton, NJ USA)
Alien megaspheres … rockets powered by nuclear bombs … freeze-dried life in outer space: These are just some of the ideas that have flowered in the brain of physicist Freeman Dyson, and he’s not done yet.
Dyson, who turned 94 last December, has spent most of his career at the Institute for Advanced Study in Princeton, N.J., and he still hangs his hat there as a professor emeritus. But he also has a connection to the Pacific Northwest: His son, tech historian George Dyson, lives in Bellingham, Wash.
The elder Dyson renews his Northwest connections on Wednesday at a Town Hall Seattle presentation that’s framed as a conversation with Seattle science-fiction author Neal Stephenson and Robbert Dijkgraaf, director of the Institute for Advanced Study.
