HEP Group Members Present Results At ICHEP 2010 Conference

First results from the Large Hadron Collider (LHC) at CERN are being revealed at ICHEP, the world's largest international conference on particle physics, which has attracted more than 1000 participants to its venue in Paris. The spokespersons of ATLAS and LHCb (two of the four major experiments at the LHC) presented measurements from the first three months of successful LHC operation at 3.5 TeV per beam, an energy three and a half times higher than previously achieved at a particle accelerator.

The Cambridge HEP group is a major partner in the experiments, in particular through the ATLAS Silicon Central Tracker, the LHCb Ring-Imaging Cherenkov detectors, software and computing and is leading the analysis of key discovery channels. Two members of the group also gave presentations at the conference: Dr Chris Lester presented "A Review of the Mass Measurement Techniques proposed for the Large Hadron Collider" Susan Haines (PhD candidate) presented "Studies of charmed hadronic B decays with early LHCb data and prospects for gamma measurements"

With these first measurements the experiments are rediscovering the particles that lie at the heart of the Standard Model - the package that contains current understanding of the particles of matter and the forces that act between them. This is an essential step before moving on to make discoveries. Among the billions of collisions already recorded are some that contain 'candidates' for the top quark, for the first time at a European laboratory.

"Rediscovering our 'old friends' in the particle world shows that the LHC experiments are well prepared to enter new territory," said CERN's Director-General Rolf Heuer. "It seems that the Standard Model is working as expected. Now it is down to nature to show us what is new."

The quality of the results presented at ICHEP bears witness both to the excellent performance of the LHC and to the high quality of the data in the experiments. The LHC, which is still in its early days, is making steady progress towards its ultimate operating conditions. The luminosity - a measure of the collision rate - has already risen by a factor of more than a thousand since the end of March. This rapid progress with commissioning the LHC beam has been matched by the speed with which the data on billions of collisions have been processed by the Worldwide LHC Computing Grid, which allows data from the experiments to be analysed at collaborating centres around the world.

"Within days we were finding Ws, and later Zs - the two carriers of the weak force discovered here at CERN nearly 30 years ago," said Fabiola Gianotti, spokesperson for the 3000-strong ATLAS collaboration. "Thanks to the efforts of the whole collaboration, in particular the young scientists, everything from data-taking at the detector, through calibration, data processing and distribution, to the physics analysis, has worked fast and efficiently."

"The LHCb experiment is tailor-made to study the family of b particles, containing beauty quarks," said the experiment's spokesperson Andrei Golutvin, "So it's extremely gratifying that we are already finding hundreds of examples of these particles, clearly pin-pointed through the analysis of many particle tracks."

CERN will run the LHC for 18-24 months with the objective of delivering enough data to the experiments to make significant advances across a wide range of physics processes. With the amount of data expected, referred to as one inverse femtobarn, the experiments should be well placed to make inroads in to new territory, with the possibility of significant discoveries.