LHC to run at 4 TeV per beam in 2012
Content: Press Release
Date Issued: 13 February 2012
Geneva, 13 February 2012. CERN* today announced that
the LHC will run with a beam energy of 4 TeV this
year, 0.5 TeV higher than in 2010 and 2011. This
decision was taken by CERN management following the
annual performance workshop held in Chamonix last
week and a report delivered today by the external
CERN Machine Advisory Committee (CMAC). It is
accompanied by a strategy to optimise LHC running to
deliver the maximum possible amount of data in 2012
before the LHC goes into a long shutdown to prepare
for higher energy running. The data target for 2012
is 15 inverse femtobarns for ATLAS and CMS, three
times higher than in 2011. Bunch spacing in the LHC
will remain at 50 nanoseconds.
"When we started operating the LHC for physics in
2010, we chose the lowest safe beam energy
consistent with the physics we wanted to do," said
CERN's Director for Accelerators and Technology,
Steve Myers. "Two good years of operational
experience with beam and many additional
measurements made during 2011 give us the confidence
to safely move up a notch, and thereby extend the
physics reach of the experiments before we go into
the LHC's first long shutdown."
The LHC's excellent performance in 2010 and 2011 has
brought tantalising hints of new physics, notably
narrowing the range of masses available to the Higgs
particle to a window of just 16 GeV. Within this
window, both the ATLAS and CMS experiments have seen
hints that a Higgs might exist in the mass range
124-126 GeV. However, to turn those hints into a
discovery, or to rule out the Standard Model Higgs
particle altogether, requires one more year's worth
of data. The LHC is scheduled to enter a long
technical stop at the end of this year to prepare
for running at its full design energy of around 7
TeV per beam.
"By the time the LHC goes into its first long stop
at the end of this year, we will either know that a
Higgs particle exists or have ruled out the
existence of a Standard Model Higgs," said CERN's
Research Director, Sergio Bertolucci. "Either would
be a major advance in our exploration of nature,
bringing us closer to understanding how the
fundamental particles acquire their mass, and
marking the beginning of a new chapter in particle
The schedule announced today foresees beams back in
the LHC next month, and running through to November.
There will then be a long technical stop of around
20 months, with the LHC restarting close to its full
design energy late in 2014 and operating for physics
at the new high energy in early 2015.
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*CERN, the European Organization for Nuclear
Research, is the world's leading laboratory for
particle physics. It has its headquarters in Geneva.
At present, its Member States are Austria, Belgium,
Bulgaria, the Czech Republic, Denmark, Finland,
France, Germany, Greece, Hungary, Italy, the
Netherlands, Norway, Poland, Portugal, Slovakia,
Spain, Sweden, Switzerland and the United Kingdom.
Romania is a candidate for accession. Israel is an
Associate Member in the pre-stage to Membership.
India, Japan, the Russian Federation, the United
States of America, Turkey, the European Commission
and UNESCO have Observer status.