Physicists fail to find sterile neutrino
The uncertainty of science: A year’s collection of data using IceCube, a gigantic neutrino telescope built in the icecap of Antarctica, has found no evidence of a theorized fourth type of neutrino.
To search for sterile neutrinos, Halzen’s team looked for the arrival of muon neutrinos that started life on the other side of Earth. These were originally produced by the collision of cosmic rays with air molecules in the atmosphere, and passed through the planet to reach the detector. The IceCube team hoped to find a dearth of muon neutrinos at particular energies. That would have suggested that some muon neutrinos had temporarily mutated into sterile neutrinos during their voyage.
But, after analysing the results of a year’s worth of data, the researchers found no feature suggesting the existence of sterile neutrinos around 1 eV. This is line with results from the European Space Agency’s Planck observatory, which concluded from cosmological evidence that there should only be three families of neutrinos in that mass range. “I hope that with our result and with the Planck result we are slowly walking our way back from this story,” says Halzen. The IceCube team are still taking data in their sterile neutrino hunt, but don’t expect their results to change, he adds.
Despite this null result, there is still a possibility that sterile neutrinos exist, but not at the mass predicted.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The uncertainty of science: A year’s collection of data using IceCube, a gigantic neutrino telescope built in the icecap of Antarctica, has found no evidence of a theorized fourth type of neutrino.
To search for sterile neutrinos, Halzen’s team looked for the arrival of muon neutrinos that started life on the other side of Earth. These were originally produced by the collision of cosmic rays with air molecules in the atmosphere, and passed through the planet to reach the detector. The IceCube team hoped to find a dearth of muon neutrinos at particular energies. That would have suggested that some muon neutrinos had temporarily mutated into sterile neutrinos during their voyage.
But, after analysing the results of a year’s worth of data, the researchers found no feature suggesting the existence of sterile neutrinos around 1 eV. This is line with results from the European Space Agency’s Planck observatory, which concluded from cosmological evidence that there should only be three families of neutrinos in that mass range. “I hope that with our result and with the Planck result we are slowly walking our way back from this story,” says Halzen. The IceCube team are still taking data in their sterile neutrino hunt, but don’t expect their results to change, he adds.
Despite this null result, there is still a possibility that sterile neutrinos exist, but not at the mass predicted.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Nice backgrounder lecture on the whole IceCube project, by Dr. Halzen himself:
“IceCube and the Discovery of High-Energy Cosmic Neutrinos”
https://youtu.be/Em_2HqIlr64
(From April, 2015)
Wow – “… muon neutrinos that started life on the other side of Earth.” – which is an amazing thing for a muon neutrino to do (!)