The University of Florida's High Energy Experimental Group is deeply involved in research at the Fermi National Laboratory (Fermilab) in Batavia, Illinois. The group consists of the following members: Professors Darin Acosta, Rick Field, Sergey Klimenko, Jacobo Konigsberg, Andrey Korytov, Guenakh Mitselmakher, Asst. Scientist Andrei Nomerotski and Graduate Student Alexei Safonov.
At this laboratory, the fundamental structure of matter and the physics laws describing its behaviour are studied. A circular particle accelerator (4 miles in circumference) produces collisions of protons and anti-protons at a center of mass energy of 1.8 TeV (1,800,000,000,000 electron Volts) at a rate of about one million collisions per second.
The Florida group works at the Collider Detector at Fermilab (CDF). This detector surrounds the collision point and particles flying out at approximately the speed of light are intercepted and identified by means of their interaction with the different sections of the detector. Their trajectories, energy and momentum are measured and the "event" is reconstructed and identified as a specific particle physics process. In 1994 this detector saw the first evidence for the existence of the last quark (the "top" quark) and in 1995, together with the D0 experiment, CDF announced the discovery of the top quark.
The Florida group is working both on the data analysis of the data accumulated from 1992 to 1994 (Run 1) and on the upgrade of the CDF detector which will allow for a factor of 20 more data in the 2000-2002 running period (Run 2).
We have been involved in the discovery of the top quark and in the understanding of the physics behaviour of this particle. We have been searching for Supersymmetry (looking for the supersymmetric partner to the top quark –the "stop" quark) and pushing the boundaries of applicability of perturbative Quantum Chromo-Dynamics (QCD) by studying the structure of highly collimated bundles of particles ("jets").
We are designing and building an innovative detector to be used in the measurement of the "beam luminosity" at the CDF interaction point during Run 2. This detector consists of two arrays of 48 long, gas filled, reflective cones, that collect Cherenkov light emitted by particles coming from the proton-antiproton collisions into photo-multiplier tubes that measure the amplitude and time of arrival of this light. We can use this information to infer the number of collisions occurring per unit time and to therefore provide a normalization to the frequency of occurrence of all other physics processes with respect to the well known, fundamental one, (inelastic proton-antiproton scattering) detected by our detector.
We are also working on extending the coverage for the detection of muons by means of a detector consisting of over 400 scintillation counters located at relatively small angles to the proton-antiproton beams. Our group participates in the design and operation of these counters as well as in the physics measurements that the detector will make feasible.
Run 2 with the CDF detector is one of the most exciting physics projects in experimental particle physics today, where the limits of knowledge will be extended and where searches for new physics will take place. The CDF Florida group is a full participant in this project since August 1996.