By Michael Banks in Washington, DC
If you are reading this blog in the hope that physicists at CERN have announced the discovery of new physics at the Large Hadron Collider (LHC) then you may be a little disappointed.
At a session this morning at the 2011 annual meeting of the American Association for the Advancement of Science, CERN researchers reflected on the past year of LHC data.
The bottom line is that the LHC has taken enough measurements to verify the Standard Model of particle physics and is now on the verge of searching for new physics.
“We are opening a door to a new landscape, starting an exploration in physics for the next 20 years.” was one of the take-home soundbites from the opening talk given by Felicitas Pauss, head of international relations at CERN.
One area of research at CERN is whether quarks – the building blocks of particles such as protons and neutrons – have any substructure.
Thomas LeCompte, from Argonne National Laboratory, told delegates that the ATLAS detector at the LHC had so far not yet spotted any evidence for quark substructure. But the emphasis is on the “yet”. CERN researchers are continously narrowing down the search.
LeCompte used a nice analogy to describe the LHC’s current limit. “If an atom is the size of an Earth, then we have not seen any evidence of substructure down to the relative size of a pea,” he says.
Indeed, LeCompte says that over the next few years, the search will narrow down to the order of a “single hundreds and thousands sprinkle”. Quite a feat.
Likewise, CERN researcher Joe Incandela noted that the CMS detector has not yet found any evidence for supersymmetry, which predicts that each fermion has a partner boson and each boson has a partner fermion – that are all known as “sparticles”. Again the emphasis is on the yet: “In 2011 we will have more than 50 times the data we have now,” he says.
Monica Pepe Altarelli from the LHCb experiment told delegates about the hunt for the a rare B-meson decay (into a muon and antimuon), which other experiments such as CDF and D0 detectors at Fermilab have searched for but not yet seen.
Altarelli notes that even with the LHC’s limited run, the collider will have recorded the production of more B-mesons than the Fermilab accelerator has managed in its whole lifetime. Altarelli also says the collaboration will publish some results in the coming days but by the end of this year they should have enough statistics to probably see glimpses of the event.
The final slide Pauss flashed up on the screen in her summary talk was an image of the Particle Physics Booklet that is published by the Institute of Physics Publishing, which owns physicsworld.com.
Pauss wondered if by the end of 2011 we will need to publish another separate book – the “sparticle physics booklet”. CERN physicists will certainly be hoping so.