<i>Test again breaks light speed</i>

A fiercely contested experiment that appears to show the accepted speed limit of the Universe can be broken has yielded the same results in a re-run, European physicists said yesterday.
But counterparts in the United States said the experiment still did not resolve doubts and the Europeans themselves acknowledged this was not the end of the story.
On September 23, the European team issued a massive challenge to fundamental physics by saying they had measured particles called neutrinos which travelled around six kilometres per second faster than the velocity of light, determined by Einstein to be the highest speed possible.
The neutrinos had been measured along a 732-kilometre (454-mile) trajectory between the European Centre for Nuclear Research (CERN) in Switzerland and a laboratory in Italy.
The scientists at CERN and the Gran Sasso Laboratory in Italy scrutinised the results of the so-called OPERA experiment for nearly six months before cautiously making the announcement.
In October, responding to criticism that they had been tricked by a statistical quirk, the team decided they would carry out a second series of experiments.
This time, the scientists altered the structure of the proton beam, a factor that critics said could have affected the outcome.
The new tests "confirm so far the previous results," the Italian Institute for Nuclear Physics (INFN) said in a press release.
In France, Jacques Martino, head of the National Institute of Nuclear and Particle Physics at the National Centre of Scientific Research (CNRS), said "the search is not over."
"There are more checks of systematics currently under discussion, one of them could be a synchronisation of the time reference at CERN and Gran Sasso independently from the GPS (Global Positioning System), using possibly a fibre."
A paper describing the re-run is published yesterday in the open-access Internet science journal, ArXiv.