by Elizabeth Lovegrove | Mar 19, 2012 | Current Events, Quick Notes
In our last update on the situation regarding OPERA’s superluminal neutrino measurement, I said that the true test of the result would be whether it stood up to independent verification. Since the controversial result was announced last November, neutrino detector experiments have scrambled to help settle the neutrino time-of-flight with their own findings. Now the first of those independent results has come in, and the outlook looks good for fans of special relativity: the ICARUS experiment, a time projection chamber located in the Gran Sasso tunnel, has made its own measurements of the same CERN beam used by OPERA, and has found no evidence of superluminal velocities.ICARUS is another experiment located in the Gran Sasso tunnel, an Italian facility buried beneath a mountain in the Apennines. Because it’s in the same place as OPERA, it can also make measurements of the beam fired from CERN. Unlike OPERA, which measures neutrinos by watching for flashes in photoscintillation material, ICARUS is a time-projection chamber. Time-projection chambers are a modern upgrade of bubble chambers, using a large cryogenic target volume (in this case, liquid argon) gridded with electronic detectors that pick up the signatures of collisions. Using this method, ICARUS looked for neutrino interactions from the widely-spaced beam that CERN switched to in late 2011. The long spacing between brief pulses – 3 ns bursts separated by 524 ns – makes it much easier for the experiments on the other end to be sure of the timing, because it’s clear which origin pulse each neutrino belongs to.According to relativistic theory, neutrinos should be moving extremely quickly because they have such small masses....
by Elizabeth Lovegrove | Nov 21, 2011 | Current Events, Daily Paper Summaries
The OPERA experiment in the Gran Sasso tunnel in Italy recently shocked the physics world by announcing that they had clocked neutrinos violating that ultimate of speed limits – the speed of light. Most scientists, upon hearing the news, rightly reacted with skepticism, and the results were closely examined to unearth any unaccounted-for sources of error that could have resulted in an incorrect measurement. On November 17th, the OPERA collaboration responded by pushing a new paper to the arXiv that eliminated one of their systematics, the length of the neutrino pulses received from CERN, and found that their data still show a significant superluminal signal.
by Shannon Hall | Dec 19, 2011 | Current Events
On 13 December 2011 CERN announced its results from ATLAS and CMS. Both experiments have made significant process in the search, but not enough to make any conclusive statement on the existence or non-existence of the Higgs boson. A definitive answer will require much more data and is likely by late 2012.
by Josh Fuchs | Dec 13, 2014 | Quick Notes
Want to figure out what to get your favorite astronomer for the holidays? Astrobites has a number of suggestions!
by Justin Vasel | Mar 3, 2012 | Daily Paper Summaries
Gamma ray bursts are high-energy events generally associated with supernova explosions in other galaxies. Though it is possible to study these events via the gamma photons that arrive here on Earth, energetic neutrinos are better suited to probe the optically-thick afterglow of gamma ray bursts and provide a more detailed description of the processes involved. This paper delves into the details of studying these neutrinos.