Tag archives: dark matter
By Hamish Johnston
There’s an interesting preprint on the arXiv server that proposes a new way of detecting dark-matter particles. I’ve been thinking about dark matter because last week physicists working on the LUX experiment announced that the underground detector had failed to find any dark-matter particles in the first three months of its operation. LUX was designed to look for WIMPs (weakly interacting massive particles), but WIMPs are not the only game in town when it comes to dark matter. There are also axions, which are the quarry of this latest proposal by three physicists in the US.
Axions are hypothetical particles that were first postulated in the 1970s to help explain puzzling aspects of quantum chromodynamics, which is the theory that describes interactions between quarks and gluons. Axions are also interesting from a cosmological point of view because they have mass but do not interact strongly with electromagnetic radiation. These properties make them prime candidates for dark matter, a mysterious substance that appears to make up most of the matter in the universe.
By Michael Banks
All eyes will be on Stockholm next week as the 2013 Nobel Prize for Physics is announced. One of the frontrunners for the prize in the minds of the Royal Swedish Academy of Sciences will surely be the discovery last year of the Higgs boson at CERN’s Large Hadron Collider (LHC).
But the LHC story is far from over and in the latest Physics World focus issue on “big science” find out how the LHC will hunt for new particles beyond the Higgs boson once the collider restarts in 2015 following an 18-month repair and upgrade programme at the Geneva-based lab.
All full members of the Institute of Physics will receive a print edition of the focus issue along with their copy of the October issue of Physics World, but everyone can access a free digital edition. The focus issue also looks at how particle physicists are already thinking about what could come after the LHC, with bold plans for a 80–100 km proton–proton collider. There are even plans for a collider based on lasers, with an international team looking at creating an array of “fibre lasers” to be used as a future “Higgs factory”.
By Hamish Johnston
A week or so ago the CDMS experiment in the US reported the detection of three possible dark-matter particles. While that might not sound like much, it is the best evidence yet that dark matter – mysterious stuff that appears to make up one quarter of the mass/energy of the universe – can be detected directly.
But as I said in an earlier blog entry, the detection further muddies the waters in terms of our understanding of exactly what dark matter is. Different experiments say very different things about its possible properties, and now a team of physicists in Denmark, the UK and Switzerland have uploaded a preprint on the arXiv server that tries to make sense of some of this speculation and contradiction.
By Hamish Johnston
Physicists working on the Cryogenic Dark Matter Search (CDMS) may have spotted three dark-matter particles in data from a detector deep beneath the North Woods of Minnesota. The measurement has a statistical significance of about 3σ – which is a long way from the gold standard of 5σ that usually heralds the discovery of a new particle. That said, this result is the best evidence yet that dark matter could be detected directly as it passes through the Earth.
By Michael Banks in Boston
The first results from the $1.5bn Alpha Magnetic Spectrometer (AMS) are expected to be released in the coming two weeks, according to AMS principal investigator Samuel Ting.
Ting, who shared the 1976 Nobel Prize for Physics, was speaking at the 2013 AAAS meeting in Boston.
Artist’s impression of a map of the Quantum Universe (Graphic courtesy of “ILC — form one visual communication”)
By Tushna Commissariat
Here’s a bit of Friday physics fun… I came across this rather interesting image that shows an artist’s impression of a map entitled “The Quantum Universe”. It includes six landmasses all floating in the Big Bang Ocean; including Dark Matter Landmass, Sypersymmetry Reef, Higgs Island and the Land of Ultimate Unification as well as others.
So go ahead and tell us which island you would like to settle down on. Be sure to look carefully at gems like Newton’s Lawn and Mount Einstein before you make your mind up!
To see a larger hi-res image follow this link.