sexta-feira, 23 de setembro de 2011

OPERA @ Gran Sasso...




A colleague of mine sent me the (official(?)) report below.


Anyway, a few (perhaps) trivia check-questions:

  • Is the tunnel or wherever the bean is observed, as it was? Has it been shortened or stretched somehow, by natural accident?
  • Are the clocks at both ends in sync?
  • Is this an exclusive muon neutrino? What about the e- and tau's? Is this mass dependent?
  • Is this effect only occurring in some sections of the beam\experiment?
  • It occurs truly random, ie, in any section (space) or period (time) or experiment\observation?
  • The 2007'Fermilab 'events' were also due to neutrinos?
  • And finally, can this be … a trivial (or not so) 'relativistic' effect? This could either be something not so funny (some sort of grav time dilation or else) or extra dimensions, right there! Funnier and more exciting: cf. Kostelecky words in the Guardian.

Anyway, neutrinos are 'weird':http://www.bbc.co.uk/news/science-environment-13763641 an right, sure, and funny to study.




Report:

Geneva, 23 September 2011. The OPERA1 experiment, which observes a neutrino beam
from CERN 730 km away at Italy’s INFN Gran Sasso Laboratory, will present new results
in a seminar at CERN this afternoon at 16:00 CEST. The seminar will be webcast at http://
webcast.cern.ch. Journalists wishing to ask questions may do so via twitter to @CERN, or via
the usual CERN press office channels.

The OPERA result is based on the observation of over 15000 neutrino events measured
at Gran Sasso, and appears to indicate that the neutrinos travel at a velocity 20 parts per
million above the speed of light, nature’s cosmic speed limit. Given the potential far-reaching
consequences of such a result, independent measurements are needed before the effect can
either be refuted or firmly established. This is why the OPERA collaboration has decided
to open the result to broader scrutiny. The collaboration’s result is available on the preprint
server arxiv.org (LINK).

This result comes as a complete surprise,” said OPERA spokesperson, Antonio Ereditato
of the University of Bern. “After many months of studies and cross checks we have not
found any instrumental effect that could explain the result of the measurement. While
OPERA researchers will continue their studies, we are also looking forward to independent
measurements to fully assess the nature of this observation.”

When an experiment finds an apparently unbelievable result and can find no artefact of the
measurement to account for it, it’s normal procedure to invite broader scrutiny, and this is
exactly what the OPERA collaboration is doing, it’s good scientific practice,” said CERN
Research Director Sergio Bertolucci. “If this measurement is confirmed, it might change our
view of physics, but we need to be sure that there are no other, more mundane, explanations.
That will require independent measurements.”

In order to perform this study, the OPERA Collaboration teamed up with experts in metrology
from CERN and other institutions to perform a series of high precision measurements of the
distance between the source and the detector, and of the neutrinos’ time of flight. The distance
between the origin of the neutrino beam and OPERA was measured with an uncertainty of
20 cm over the 730 km travel path. The neutrinos’ time of flight was determined with an
accuracy of less than 10 nanoseconds by using sophisticated instruments including advanced
GPS systems and atomic clocks. The time response of all elements of the CNGS beam line
and of the OPERA detector has also been measured with great precision.

"We have established synchronization between CERN and Gran Sasso that gives us

1 OPERA has been designed and is being conducted by a team of researchers from Belgium, Croatia, France, Germany,

Israel, Italy, Japan, Korea, Russia, Switzerland and Turkey. The experiment constitutes a complex scientific enterprise that
has been realised thanks to the skill of a large number of scientists, engineers, technicians and students, and with the strong
commitment of the various actors of the project. In particular we mention the LNGS/INFN and CERN laboratories, and the
major financial support of Italy and Japan with substantial contributions from Belgium, France, Germany and Switzerland.
The OPERA Collaboration presently includes about 160 researchers from 30 institutions and 11 countries:
IIHE-ULB Brussels, Belgium; IRB Zagreb, Croatia; LAPP Annecy, France; IPNL Lyon, France; IPHC Strasbourg, France;
Hamburg, Germany; Technion Haifa, Israel; Bari, Italy; Bologna, Italy; LNF, Italy, L’Aquila, Italy; LNGS, Italy; Naples,
Italy; Padova, Italy; Rome, Italy; Salerno, Italy; Aichi, Japan; Toho, Japan; Kobe, Japan; Nagoya, Japan; Utsunomiya, Japan;
GNU Jinju, Korea; INR RAS Moscow, Russia; LPI RAS Moscow, Russia; ITEP Moscow, Russia; SINP MSU Moscow,
Russia; JINR Dubna, Russia; Bern, Switzerland; ETH Zurich, Switzerland; METU Ankara, Turkey.

nanosecond accuracy, and we’ve measured the distance between the two sites to 20
centimetres,” said Dario Autiero, the CNRS researcher who will give this afternoon’s
seminar. “Although our measurements have low systematic uncertainty and high statistical
accuracy, and we place great confidence in our results, we’re looking forward to comparing
them with those from other experiments."

The potential impact on science is too large to draw immediate conclusions or attempt
physics interpretations. My first reaction is that the neutrino is still surprising us with its
mysteries.” said Ereditato. “Today’s seminar is intended to invite scrutiny from the broader
particle physics community.”

The OPERA experiment was inaugurated in 2006, with the main goal of studying the rare
transformation (oscillation) of muon neutrinos into tau neutrinos. One first such event was
observed in 2010, proving the unique ability of the experiment in the detection of the elusive
signal of tau neutrinos.

Further information:

Link to OPERA statement
Link to OPERA website
Link to blog post
Link to video

Press office contact details



The Honourable Schoolboy

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