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Posts Tagged ‘matter and antimatter’

CERN’s ALPHA Experiment Measures Charge Of Antihydrogen


Geneva, 3 June 2014. In a paper published in the journal Nature Communications today, the ALPHA experiment at CERN1’s Antiproton Decelerator (AD) reports a measurement of the electric charge of antihydrogen atoms, finding it to be compatible with zero to eight decimal places. Although this result comes as no surprise, since hydrogen atoms are electrically neutral, it is the first time that the charge of an antiatom has been measured to high precision.

“This is the first time we have been able to study antihydrogen with some precision,” said ALPHA spokesperson Jeffrey Hangst. “We are optimistic that ALPHA’s trapping technique will yield many such insights in the future. We look forward to the restart of the AD program in August, so that we can continue to study antihydrogen with ever increasing accuracy.”

Antiparticles should be identical to matter particles except for the sign of their electric charge. So while the hydrogen atom is made up of a proton with charge +1 and an electron with charge -1, the antihydrogen atom consists of a charge -1 antiproton and a charge +1 positron. We know, however, that matter and antimatter are not exact opposites – nature seems to have a one-part in 10 billion preference for matter over antimatter, so it is important to measure the properties of antimatter to great precision: the principal goal of CERN’s AD experiments. ALPHA achieves this by using a complex system of particle traps that allow antihydrogen atoms to be produced and stored for long enough periods to study in detail. Understanding matter antimatter asymmetry is one of the greatest challenges in physics today. Any detectable difference between matter and antimatter could help solve the mystery and open a window to new physics.

Link To Full Story

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.”

Full Story: http://www.stfc.ac.uk/2802.aspx

Exotic Atoms Hold Clues To Unsolved Physics Puzzle At The Dawn Of The Universe


An international team of physicists has found the first direct evidence of pear shaped nuclei in exotic atoms.

The findings could advance the search for a new fundamental force in nature that could explain why the Big Bang created more matter than antimatter—a pivotal imbalance in the history of everything.

“If equal amounts of matter and antimatter were created at the Big Bang, everything would have annihilated, and there would be no galaxies, stars, planets or people,” said Tim Chupp, a University of Michigan professor of physics and biomedical engineering and co-author of a paper on the work published in the May 9 issue of Nature.

Antimatter particles have the same mass but opposite charge from their matter counterparts. Antimatter is rare in the known universe, flitting briefly in and out of existence in cosmic rays, solar flares and particle accelerators like CERN’s Large Hadron Collider, for example. When they find each other, matter and antimatter particles mutually destruct or annihilate.

What caused the matter/antimatter imbalance is one of physics’ great mysteries. It’s not predicted by the Standard Model—the overarching theory that describes the laws of nature and the nature of matter.

Full Story: http://ns.umich.edu/new/releases/21453-exotic-atoms-hold-clues-to-unsolved-physics-puzzle-at-the-dawn-of-the-universe

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.

Full Story: http://newscenter.berkeley.edu/2012/03/08/new-discovery-key-to-understanding-neutrino-transformation/