A timeline with news stories, papers, tweets and blog posts about the faster-than-light neutrinos story.
Created by kahoakes on 03/12/2011
Last updated: 23/02/12 at 10:02
OPERA released a short official statement on the nature of the "dodgy wiring" problem. It looks like there were in fact two issues with the original experimental set up, which would have worked in opposite directions. It still remains to be seen whether they will explain the 60ns discrepancy seen in the original experiment.
http://blogs.scientificamerican.com/basic-space/2012/02/22/faster-than-light-neutrinos-explained/
"The OPERA collaboration [...] has identified two possible sources of error in its experiment."
“The OPERA Collaboration, by continuing its campaign of verifications on the neutrino velocity measurement, has identified two issues that could significantly affect the reported result. The first one is linked to the oscillator used to produce the events time-stamps in between the GPS synchronizations. The second point is related to the connection of the optical fiber bringing the external GPS signal to the OPERA master clock.
These two issues can modify the neutrino time of flight in opposite directions. While continuing our investigations, in order to unambiguously quantify the effect on the observed result, the Collaboration is looking forward to performing a new measurement of the neutrino velocity as soon as a new bunched beam will be available in 2012. An extensive report on the above mentioned verifications and results will be shortly made available to the scientific committees and agencies.”
Caren Hagner, a member of OPERA at the University of Hamburg in Germany, says “For the moment the collaboration decided not to make a quantitative statement, because we have to recheck and discuss the findings more thoroughly.”
http://blogs.nature.com/news/2012/02/faster-than-light-neutrino-measurement-has-two-possible-errors.html
Science report that "bad wiring" might have caused the faster-than-light neutrino result.
http://news.sciencemag.org/scienceinsider/2012/02/breaking-news-error-undoes-faster.html
My post about the dodgy wiring rumours and update from OPERA.
http://blogs.scientificamerican.com/basic-space/2012/02/22/faster-than-light-neutrinos-explained/
Claudio Germana shows that the reported delay between the expected photon and neutrino arrival times can be explained by the effects of transforming from an Earth based clock to an inertial frame.
http://www.aanda.org/index.php?option=com_article&access=doi&doi=10.1051/0004-6361/201118745&Itemid=129
Press release for Cowsik, Nussinov and Sarkar's paper on pion decay.
http://news.wustl.edu/news/Pages/23154.aspx
Paper by Ramanath Cowsik, Shmuel Nussinov and Utpal Sarkar.
Cowsik said: “We’ve shown in this paper that if the neutrino that comes out of a pion decay were going faster than the speed of light, the pion lifetime would get longer, and the neutrino would carry a smaller fraction of the energy shared by the neutrino and the muon.”
“So we are saying that in the present framework of physics, superluminal neutrinos would be difficult to produce."
http://prl.aps.org/abstract/PRL/v107/i25/e251801
Abstract: The superluminal is reported in OPERA neutrino experiment (arXiv:1109.4897v2), this result is consistent with previous MINOS experiment about neutrino velocity (Phys. Rev. D 76, 072005 (2007)). Here we propose a Dirac equation of tachyon for superluminal neutrino in which the mass matrix is anti-hermitian. Additionally we find that this anti-hermitian mass matrix which is responsible for superluminal can only be for neutrinos, while other results of Standard Model are unchanged. In case that Lorentz invariant is remained, the masses of neutrinos are estimated based on available data of experiments.
http://arxiv.org/abs/1110.1943
http://www.guardian.co.uk/science/2011/nov/21/faster-than-light-neutrinos-doubts
http://www.jimal-khalili.com/blog/faster-than-the-speed-of-light.html
Abstract:
Considering the OPERA neutrino-velocity measurement from the point of view of a GPS satellite we find that the detector at Gran Sasso has a velocity component in the order of $10^{-5}c$ towards the neutrino emission location at CERN. On GPS-receivers this translates into first-order Doppler terms, therefore a correction is required for, among other things, this ephemeris-and-location-dependent relativistic effect. To ensure correct time-of-flight measurements using satellite-based clocks we propose to extend their calibration procedures with an explicit check on these relativistic corrections.
http://arxiv.org/abs/1110.2685
Abstract: The new data release of OPERA - CNGS experiment, obtained with a shorter spill of protons, confirms the tachyionic behavior expected from the phenomenological model of a Majorana neutrino with a fictitious imaginary mass term acquired during the propagation in the Earth's crust, recently presented by us. We performed numerical simulations of neutrino event detections to compare the properties of these Majorana tachyons with the new OPERA results, finding a good agreement. The possibility of spin-to orbital angular momentum conversion that is expected to give a negative squared mass in a medium, is also briefly discussed.
http://arxiv.org/abs/1111.4441.pdf
http://www.guardian.co.uk/science/2011/nov/18/neutrinos-still-faster-than-light
OPERA re-ran the experiment, taking into account some (but not all) of the criticism levelled at the first paper.
http://arxiv.org/abs/1109.4897v2
Abstract: From the data release of OPERA - CNGS experiment, and publicly announced on 23 September 2011, we cast a phenomenological model based on a Majorana neutrino state carrying a fictitious imaginary mass term, already discussed by Majorana in 1932. This mass term can be induced by the interaction with the matter of the Earth's crust during the 735 Km travel. Within the experimental errors, we prove that the model fits with OPERA, MINOS and supernova SN1987a data. Possible violations to Lorentz invariance due to quantum gravity effects have been considered.
http://arxiv.org/abs/1109.5445
Paper by Andrew Cohen and Sheldon Glashow. Cohen and Glashow say that if the neutrinos had travelled faster than light, they should have lost energy through releasing pairs of electrons and positrons.
The Icarus experiment, situated at Gran Sasso laboratory with Operia, looked for this predicted energy loss but did not find any evidence of it.
http://prl.aps.org/abstract/PRL/v107/i25/e251801
The ICARUS collaboartion at Gran Sasso tested Sheldon and Glashow's predictions (published on arXiv before they reached Physical Review Letters) and found no energy loss — indicating that the neutrinos did not travel faster than light.
First version uploaded on 17 October, latest version on 22 October.
http://arxiv.org/abs/1110.3763v1
Abstract: We found three mistakes in the article " The OPERA neutrino velocity result and the synchronisation of clocks" by Contaldi \cite{Contaldi}. First, the definition of the angle of the latitude in the geoid description leads to a prolate spheroid (rugby ball shape) instead of an oblate spheroid with the usual equatorial flattening. Second, Contaldi forgot a cosine of the latitude in the centripetal contribution term. And last but not least, a profound conceptual mistake was done in believing that an atomic clock or any timekeeper apparatus was carried in a journey by car or plane between CERN and Gran Sasso; instead of that atomic clocks are continuously resynchronized through a GPS device, and the variation of the potential term applies only for the neutrino travel itself. Thus instead of a $\Delta t \approx 30ns $ correction claimed by the author in a travel of 12 hours plus 4 days at rest for an atomic clock, we have found a time correction only for the neutrino itself $\Delta t=3.88 \, 10^{-16} s$! That means, that this paper \cite{Contaldi} does not give the right explanation why the neutrino is seen travelling faster than the speed of light in the OPERA neutrino experiment.
http://arxiv.org/abs/1110.2909
Nature article on Carlo Contaldi's paper pointing out a possible problem with the synchronisation of the clocks in Geneva and Gran Sasso.
http://www.nature.com/news/2011/111005/full/news.2011.575.html
Gilles Henri of the Institute of Planetary Science and Astrophysics in Grenoble, France, posted a paper on arXiv arguing that "the beam composition [varying] during the leading and the trailing edges" can explain the time difference without resorting to faster-than-light travel.
http://arxiv.org/abs/1110.0239
Dr Carlo Contaldi of Imperial College published a paper on the pre-print server arXiv.org arguing that "the effect of the synchronisation convention is not properly taken into account in the OPERA analysis".
http://xxx.lanl.gov/abs/1109.6160
My take on the results, and how they show the process of science.
http://blogs.scientificamerican.com/basic-space/2011/09/23/faster-than-light-neutrinos-show-science-in-action/
Includes audio interview with OPERA spokesperson Antonio Ereditato and graphic illustrating key facts about the experiment.
http://www.bbc.co.uk/news/science-environment-15017484
CERN held a seminar, which they streamed live and recorded, after the initial announcement of the result. You can watch it here.
http://cdsweb.cern.ch/record/1384486?ln=en
http://twitter.com/#!/jimalkhalili/status/117160630527594496
Dr Ben Still on what previous supernova observations tell us about the speed of neutrinos.
http://neutrinoscience.blogspot.com/2011/09/arriving-fashionable-late-for-party.html
The almost-superluminal Randal Munroe had a comic up before most news outlets had even published a story about the result.
http://xkcd.com/955/
http://www.guardian.co.uk/science/2011/sep/22/faster-than-light-particles-neutrinos
Nature has a news article up the same day, with a somewhat dubious headline
http://www.nature.com/news/2011/110922/full/news.2011.554.html
The original paper that the OPERA experiment uploaded to pre-print server arXiv.org
http://arxiv.org/abs/1109.4897v1
Ethan Seigel at Starts With A Bang explains the physics behind the experiment.
http://scienceblogs.com/startswithabang/2011/09/this_extraordinary_claim_requi.php
http://twitter.com/#!/ReutersScience/status/116918703513284608
Reuters press release breaks the news about the faster-than-light neutrinos, before the pre-print is uploaded to arXiv.org
http://www.reuters.com/article/2011/09/22/us-science-light-idUSTRE78L4FH20110922?feedType=RSS&feedName=scienceNews&dlvrit=309301
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