imatfaal Posted April 3, 2013 Posted April 3, 2013 The long awaited and trailed announcement from the AMS Collaboration is imminent SPECIAL CERN-EP Seminar on Wednesday 3rd of April 2013"Recent results from the AMS experiment"by Prof. Samuel TING (Massachusetts Inst. Of Technology (US)) https://indico.cern.ch/conferenceDisplay.py?confId=244334 NASA TV BRIEFING DISCUSSES ALPHA MAGNETIC SPECTROMETER RESULTSNASA will hold a news conference at 1:30 p.m. EDT on Wednesday, April 3, to discuss the first results of the Alpha Magnetic Spectrometer (AMS) experiment.For NASA TV streaming video, scheduling and downlink information, visit:http://www.nasa.gov/ntv AMS Draft Press Announcement (cannot find final version) http://ams.nasa.gov/Documents/AMS_Publications/Draft%20Press%20ReleaseVs3.pdf BBC - http://www.bbc.co.uk/news/science-environment-22016504 Nature http://www.nature.com/news/space-station-experiment-deepens-antimatter-enigma-1.12718 Space,com http://www.space.com/20488-nasa-astrophysics-discovery-ams.html (although can you trust an astro site that cannot convert EDT to GMT???) Science Magazine http://news.sciencemag.org/sciencenow/2013/04/two-billion-dollar-cosmic-ray-de.html The know-nothing bozzo version is a little disappointing. What the AMS Colab are announcing is at present confirmation of the previously hinted at positron excess - more positrons (anti matter electrons) than would be expected in open space. This is not new but previous evidence was compromised and unconvincing. The AMS detects from the whole sky (so rules out a localized source), was designed to tell positrons from electrons (so does not suffer from the possible problem of using deflecting by earths magnetic field to distinguish), and can accurately tell that these are the light positrons rather than much heavier protons. From my early reading this confirmation of (lower energy) positron excess is well documented and evidence by the AMS data and is accurate to a high significance. The more interesting bit is that the theory suggested that the level of positron excess should fall with measured energy - but it clearly shows a dip and rise. There is something which is annihilating or decaying to positrons which is outside of current theory. The idea is that this unknown is dark matter. Even more speculative is the fact that after a rise - at around 250-300 GeV - the curve starts to flatten off. It would make sense that you cannot get dark matter particles to produce positrons of a higher energy than the parent particle - is this flattening off the sign of the energy of a dark matter particle? Background on excess http://arxiv.org/abs/0810.5344 Pamela paper - first to spot the excess (limited by proton/positron confusion) https://news.slac.stanford.edu/features/fermi-gamma-ray-space-telescope-confirms-puzzling-preponderance-positrons Fermi Gay Ray confirmation of Pamela (used earths magnetic field to tell difference) 2
Recommended Posts