The Lancaster ATLAS Group

The Lancaster ATLAS group is heavily involved with understanding the early data from the ATLAS experiment at the CERN Large Hadron Collider.

We had a major role in the development and construction of the tracking detectors, and we have an important role in the development of tracking software. We also lead the ATLAS UK Computing Project and have leadership roles in the experiment itself.

More information on this experiment is available here .

The Lancaster Group has a major role in the study of particles called the J/Ψ. These particles have been known for a long time, and their properties are very well understood. This means they are ideal for understanding the detector, in particular the tracking and the muon detection. It also allows us to understand some of the important triggers, which are the means by which the huge rate of collisions are reduced to a much lower rate that can be stored, reconstructed and analysed.

Understanding how these particles are produced in these new very high energy proton-proton collisions is important to the understanding of any new physics processes, and is interesting in itself.

In the longer term, these particles are key to some of the more important B-physics decays that will be used to look for new physics and to study the question of the matter/antimatter asymmetry of the Universe and CP-violation. Lancaster is home to the current B physics co-ordinator and a previous B-physics co-ordinator.

The Lancaster group is also studying the searches for new particles that decay into top quarks, which in turn decay into jets of particles. In related work, they are also responsible for determining the precise position of the original collision in the detectors.

In another strand of research, Lancaster is searching for the Higgs boson, a particle associated with the mechanism believed to give all particles mass. It is studying this by looking at decays to leptons, particularly tau leptons, and uses experience gained in the D-Zero experiment at Fermilab.

Latest Progress from ATLAS

You can find more general information aimed at the press and public at the ATLAS public pages

If you combine two jets of particles and assume they come from a decaying object, you can work out the mass of that object. . If many events appear with a similar mass, it suggests the presence of a new particle.The following picture shows the highest mass di-jet ever recorded.

The Lancaster group studies the many J/Ψ particle produced and their decays to muons. The following picture shows en event with one such decay, and we now have an unprecedented number of reconstructed decays of Bs mesons to a J/Ψand a φ which will open the door to measurements of so-called CP violation.

We have already shown our understanding of the detector and the data with measurements of the Bs lifetime.

ATLAS is already identifying the many jets from top quarks, and using them in searches for new particles. An example event with a top jet is given below.

Group Members on ATLAS

Core staff

Guennadi Borrisov

Harald Fox

Roger Jones (group leader)

Vato Kartvelishvili

Rob Henderson

Maria Smizanska

Peter Love

Alex Chilingarov

RAs

Eva Bouhova

Katy Tchann-Grimm

James Walder

Postgraduate students

Robin Long

Adam Burton

Lee Allison

Will Dearneley

Harvey Maddocks