LUX dark matter results confirmed
A new calibration technique fired neutrons directly into the Large Underground Xenon dark matter detector, increasing calibration accuracy by a factor of 10. Analysis based on the calibration confirms that if “low-mass” dark matter particles had passed through the detector during its initial run, Large Underground Xenon would have seen them.
The first dark matter search results from LUX detector were announced last October. The detector proved to be exquisitely sensitive, but found no evidence of the dark matter particles during its first 90-day run, ruling out a wide range of possible models for dark matter particles. Previous experiments had detected potential signatures of dark matter particles with a very low mass, but LUX turned up no such signal. This latest work was focused on demonstrating the high sensitivity of LUX to potential signals in the search for those low-mass particles.
http://phys.org/news/2014-02-lux-dark-results.html#jCp
Cern considers building huge physics machine
The possibility of building an underground “atom-smasher” four times the size of the Large Hadron Collider is to be explored by experts.
“Take as an example the LHC. It is just three years into full swing, but the real discussions on the LHC started in 1983; the first meeting on the physics in 1984. And the first data were taken in 2009. So we need a long lead time. And that’s why we start now to kick off this project.”
The 100km Cern tunnel is just one of several proposals to be considered following the “kick-off” meeting being held this week. Japan and China are also interested in hosting giant international colliders, though the European advocates argue Cern’s established infrastructure would deliver substantial savings, and greater certainty over its success.
http://www.bbc.co.uk/news/science-environment-26250716
DARPA Opens Treasure Trove Of Data And Software
The Defense Advanced Research Projects Agency (DARPA) has created an open catalog containing results of its sponsored research in computer science.
As a result of requests from the R&D community, DARPA has created the DARPA Open Catalog, a place for organizing and sharing those results in the form of software, publications, data and experimental details. It contains the results of the programs that DARPA has invested in, covering both fundamental and applied research in computer science.
Most precise measurement of electron mass made
Scientists in Germany said Wednesday they had made the most precise measurement yet of the mass of the electron, one of the building blocks of matter.
A team led by Sven Sturm of the Max Planck Institute for Nuclear Physics in Heidelberg “weighed” electrons using a device called a Penning trap, which stores charged particles in a combination of magnetic and electrical fields.
They measured a single electron that was bound to a carbon nucleus whose mass was already known.
The electron has 0.000548579909067 of an atomic mass unit, the measurement unit for particles, according to the calculation, which factors in variables for statistical and experimental uncertainties.
http://phys.org/news/2014-02-precise-electron-mass.html#jCp
Physicists benchmark quantum simulator with hundreds of qubits (April 2012)
Physicists at the National Institute of Standards and Technology (NIST) have built a quantum simulator that can engineer interactions among hundreds of quantum bits (qubits) — 10 times more than previous devices. As described in the April 26 issue of Nature, the simulator has passed a series of important benchmarking tests and scientists are poised to study problems in material science that are impossible to model on conventional computers.
The NIST simulator consists of a tiny, single-plane crystal of hundreds of beryllium ions, less than 1 millimeter in diameter, hovering inside a device called a Penning trap. The outermost electron of each ion acts as a tiny quantum magnet and is used as a qubit — the quantum equivalent of a “1” or a “0” in a conventional computer. In the benchmarking experiment, physicists used laser beams to cool the ions to near absolute zero. Carefully timed microwave and laser pulses then caused the qubits to interact, mimicking the quantum behavior of materials otherwise very difficult to study in the laboratory. Although the two systems may outwardly appear dissimilar, their behavior is engineered to be mathematically identical. In this way, simulators allow researchers to vary parameters that couldn’t be changed in natural solids, such as atomic lattice spacing and geometry. In the NIST benchmarking experiments, the strength of the interactions was intentionally weak so that the simulation remained simple enough to be confirmed by a classical computer. Ongoing research uses much stronger interactions.
