Tag Archives: IceCube

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.

New data from a neutrino telescope in Antarctica had found that cosmic rays don’t come from gamma ray bursts, as had been believed by astronomers.

The uncertainty of science: New data from a neutrino telescope in Antarctica has found that cosmic rays don’t come from gamma ray bursts, as had been believed by astronomers. You can read the paper here. [pdf]

Which means that astronomers at this moment have no idea what produces these high energy cosmic rays.