[time-nuts] Neutrinos not faster than light

[Javier Serrano]

On Fri, Mar 16, 2012 at 11:44 PM, Javier Herrero <jherrero at hvsistemas.es> wrote:
> Hello,
> Javier Serrano can confirm it for sure, but I think that the article with
> the OPERA results is based on data from 2009 to 2011, not from data taken
> the previous day :)

Exactly.  OPERA first published a result based on several years of
data taking prior to the summer 2011. These results were criticized on
several fronts, most of which had to do with the 10us-wide proton
distribution at the exit of CERN's Super Proton Synchrotron (SPS).
Then it was decided to have a short run in December 2011 with
524ns-spaced proton bunches, so that neutrinos detected in Laboratori
Nazionali del Gran Sasso (LNGS) could be unequivocally assigned to a
single bunch. These bunches are around 1ns-wide. I think the four
experiments in LNGS (OPERA, Icarus, Borexino and LVD) saw neutrino
events during that run. For OPERA, these events confirmed their
previous result, and they extended their original paper accordingly.
This now is the publication of the Icarus results, based on 7 neutrino
events. The time link between CERN's SPS and Icarus is different from
the CERN-OPERA link only in the last stretch, where the dedicated
OPERA and Icarus data-taking electronics reside. It's soon to conclude
where the difference in results could come from. I personally don't
know that last stretch well enough to comment. In any case, we will
have another dedicated run with spaced bunches later in the Spring,
and then all four experiments will be ready to publish a result quite
quickly. In addition, our American friends in Fermilab and MINOS
should be able to get a result as well some time in 2012. So we're
entering now some very interesting months!

Cheers,

Javier