At a seminar held at CERN1 today as a curtain raiser to the
year’s major particle physics conference, ICHEP2012 in Melbourne, the ATLAS and
CMS experiments presented their latest preliminary results in the search for
the long sought Higgs particle. Both experiments observe a new particle in the
mass region around 125-126 GeV.
“We observe in our data clear signs of a new particle, at
the level of 5 sigma, in the mass region around 126 GeV.
The outstanding
performance of the LHC and ATLAS and the huge efforts of many people have
brought us to this exciting stage,” said ATLAS experiment spokesperson Fabiola
Gianotti, “but a little more time is needed to prepare these results for
publication.”
"The results are preliminary but the 5 sigma signal at
around 125 GeV we’re seeing is dramatic. This is indeed a new particle.
We know
it must be a boson and it’s the heaviest boson ever found,” said CMS experiment
spokesperson Joe Incandela.
“The implications are very significant and it is
precisely for this reason that we must be extremely diligent in all of our
studies and cross-checks."
“It’s hard not to get excited by these results,” said CERN
Research Director Sergio Bertolucci.
“ We stated last year that in 2012 we
would either find a new Higgs-like particle or exclude the existence of the
Standard Model Higgs. With all the necessary caution, it looks to me that we
are at a branching point: the observation of this new particle indicates the
path for the future towards a more detailed understanding of what we’re seeing
in the data.”
The results presented today are labelled preliminary.
They
are based on data collected in 2011 and 2012, with the 2012 data still under
analysis.
Publication of the analyses
shown today is expected around the end of July. A more complete picture of
today’s observations will emerge later this year after the LHC provides the
experiments with more data.
The next step will be to determine the precise nature of the
particle and its significance for our understanding of the universe.
Are its properties
as expected for the long-sought Higgs boson, the final missing ingredient in
the Standard Model of particle physics?
Or is it something more exotic? The
Standard Model describes the fundamental particles from which we, and every
visible thing in the universe, are made, and the forces acting between them.
All the matter that we can see, however, appears to be no more than about 4% of
the total.
A more exotic version of the Higgs particle could be a bridge to
understanding the 96% of the universe that remains obscure.
“We have reached a milestone in our understanding of
nature,” said CERN Director General Rolf Heuer.
“The discovery of a particle
consistent with the Higgs boson opens the way to more detailed studies,
requiring larger statistics, which will pin down the new particle’s properties,
and is likely to shed light on other mysteries of our universe.”
Positive identification of the new particle’s
characteristics will take considerable time and data.
But whatever form the
Higgs particle takes, our knowledge of the fundamental structure of matter is
about to take a major step forward.
ress.web.cern.ch
