Posts Tagged ‘neutrinos’

Mysterious X-Ray Signal Intrigues Astronomers

Credit: X-ray: NASA/CXC/SAO/E.Bulbul, et al.

Credit: X-ray: NASA/CXC/SAO/E.Bulbul, et al.

A mysterious X-ray signal has been found in a detailed study of galaxy clusters using NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton. One intriguing possibility is that the X-rays are produced by the decay of sterile neutrinos, a type of particle that has been proposed as a candidate for dark matter.

While holding exciting potential, these results must be confirmed with additional data to rule out other explanations and determine whether it is plausible that dark matter has been observed.

Astronomers think dark matter constitutes 85% of the matter in the Universe, but does not emit or absorb light like “normal” matter such as protons, neutrons and electrons that make up the familiar elements observed in planets, stars, and galaxies. Because of this, scientists must use indirect methods to search for clues about dark matter.

The latest results from Chandra and XMM-Newton consist of an unidentified X-ray emission line, that is, a spike of intensity at a very specific wavelength of X-ray light. Astronomers detected this emission line in the Perseus galaxy cluster using both Chandra and XMM-Newton. They also found the line in a combined study of 73 other galaxy clusters with XMM-Newton.

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Massive Neutrinos Solve A Cosmological Conundrum

February 10, 2014 Leave a comment

Galaxy2-Cropped-445x124_smScientists have solved a major problem with the current standard model of cosmology by combining results from the Planck spacecraft and measurements of gravitational lensing to deduce the mass of ghostly sub-atomic particles called neutrinos.

The team, from the universities of Nottingham and Manchester, used observations of the Big Bang and the curvature of space-time to accurately measure the mass of these elementary particles for the first time.

The recent Planck spacecraft observations of the Cosmic Microwave Background (CMB) – the fading glow of the Big Bang – highlighted a discrepancy between these cosmological results and the predictions from other types of observations.

The CMB is the oldest light in the Universe, and its study has allowed scientists to accurately measure cosmological parameters, such as the amount of matter in the Universe and its age. But an inconsistency arises when large-scale structures of the Universe, such as the distribution of galaxies, are observed.

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Neutrinos On Ice Now The Coolest New Astronomy Tool

November 21, 2013 Leave a comment

The IceCube Lab. Credit: Sven Lidstrom. IceCube/NSF

The IceCube Lab. Credit: Sven Lidstrom. IceCube/NSF

A massive telescope buried in the Antarctic ice has detected 28 record-breaking, extremely high-energy neutrinos — elementary particles that likely originate outside our solar system. The achievement, which comes nearly 25 years after the pioneering idea of detecting neutrinos in ice, provides the first solid evidence for astrophysical neutrinos from cosmic accelerators and has been hailed as the dawn of a new age of astronomy. The team researchers that detected the neutrinos with the new IceCube Neutrino Observatory in Antarctica, which includes Penn State scientists, will publish a paper describing the detections on 22 November 2013 in the journal Science.

“While it is premature to speculate about the precise origin of these neutrinos, their energies are too high to be produced by cosmic rays interacting in the Earth’s atmosphere, strongly suggesting that they are produced by distant accelerators of subatomic particles elsewhere in our galaxy, or even farther away,” said Penn State Associate Professor of Physics Tyce DeYoung, the deputy spokesperson of the IceCube Collaboration.

The neutrinos had energies greater than 1,000,000,000,000,000 electron volts or, as the scientists say, 1 peta-electron volt (PeV). Two of these neutrinos had energies many thousands of times higher than the highest-energy neutrino that any man-made particle accelerator has ever produced.

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UK Researchers Make New Discovery About Neutrinos, Bringing Us One Step Closer To Perhaps Solving One Of The Biggest Mysteries In Fundamental Physics

International research including the UK and Japan has confirmed that subatomic particles called neutrinos have a new form of identity-shifting property. Announced today (19 July 2013) these results could one day help scientists explain why the universe contains matter but very little antimatter.

Dr Alfons Weber, Professor of Physics at STFC and the University of Oxford is one of many scientists in the UK working on T2K – he designed the electronics for the experiment. He explains: “The UK particle physics community was one of the driving forces behind this experiment. We not only provided part of the detector that characterises the beam, but also designed the target that produces the neutrinos in the first place. The long years of hard work have now come to fruition.

“Our findings now open the possibility to study this process for neutrinos and their antimatter partners, the anti-neutrinos. A difference in the rate of electron or anti-electron neutrino being produced may lead us to understand why there is so much more matter than antimatter in the universe. The neutrino may be the very reason we are here.”

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New Discovery About Neutrino Oscillations

March 12, 2012 Leave a comment

A new discovery provides a crucial key to understanding how neutrinos – ghostly particles with multiple personalities – change identity and may help shed light on why matter exists in the universe.

In an announcement today (Thursday, March 8), members of the large international Daya Bay collaboration reported the last of three measurements that describe how the three types, or flavors, of neutrinos blend with one another, providing an explanation for their spooky morphing from one flavor to another, a phenomenon called neutrino oscillation.

The measurement makes possible new experiments that may help explain why the present universe is filled mostly with matter, and not equal parts of matter and antimatter that would have annihilated each other to leave behind nothing but energy. One theory is that a process shortly after the birth of the universe led to the asymmetry, but a necessary condition for this is the violation of charge-parity (or CP) symmetry. If neutrinos and their antimatter equivalent, antineutrinos, oscillate differently, this could provide the explanation.

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Faster-Than-Light Neutrinos Re-Tested: Same Result

November 18, 2011 1 comment

A fiercely contested experiment that appears to show the accepted speed limit of the Universe can be broken has yielded the same results in a re-run, European physicists said.

But counterparts in the United States said the experiment still did not resolve doubts and the Europeans themselves acknowledged this was not the end of the story.

On Sept. 23, the European team issued a massive challenge to fundamental physics by saying they had measured particles called neutrinos which traveled around six kilometers (3.75 miles) per second faster than the speed of light, determined by Einstein to be the highest velocity possible.

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Next Step in Design of LAGUNA Neutrino Observatory

October 18, 2011 Leave a comment

The kick-off meeting for the second phase of the LAGUNA’s design study starts today at CERN. The principal goal of LAGUNA (Large Apparatus for Grand Unification and Neutrino Astrophysics) is to assess the feasibility of a new pan-European research infrastructure able to host the next generation, very large volume, deep underground neutrino observatory. The scientific goals of such an observatory combine exciting neutrino astrophysics with research addressing several fundamental questions such as proton decay and the existence of a new source of matter-antimatter asymmetry in Nature, in order to explain why our Universe contains only matter and not equal amounts of matter and antimatter.

Underground neutrino detectors based on large, surface-instrumented, liquid volumes have achieved fundamental results in particle and astroparticle physics, and were able to simultaneously collect events from several different cosmic sources. Neutrinos interact only very weakly with matter so they can travel very large distances in space and traverse dense zones of the Universe, thus providing unique information on their sources and an extremely rich physics programme.

In order to move forward, a next-generation very large multipurpose underground neutrino observatory of a total mass of around 100 000 to 500 000 tons is needed. This new facility will provide new and unique scientific opportunities, very likely leading to fundamental discoveries and attracting interest from scientists worldwide.

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Particles break light-speed limit

September 22, 2011 2 comments

An Italian experiment has unveiled evidence that fundamental particles known as neutrinos can travel faster than light. Other researchers are cautious about the result, but if it stands further scrutiny, the finding would overturn the most fundamental rule of modern physics — that nothing travels faster than 299,792,458 metres per second.

The experiment is called OPERA (Oscillation Project with Emulsion-tRacking Apparatus), and lies 1,400 metres underground in the Gran Sasso National Laboratory in Italy. It is designed to study a beam of neutrinos coming from CERN, Europe’s premier high-energy physics laboratory located 730 kilometres away near Geneva, Switzerland. Neutrinos are fundamental particles that are electrically neutral, rarely interact with other matter, and have a vanishingly small mass. But they are all around us — the Sun produces so many neutrinos as a by-product of nuclear reactions that many billions pass through your eye every second.

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