Particle Physics research is about understanding what our Universe is made of and how it came to be as it is today. Today we know that there are 2 kinds of matter, leptons and quarks, and that there are four forces that mediate their interactions: the electromagnetic, the strong the weak and the gravitational force. We also have a theoretical model which we call the “Standard Model” that tells us about the strength of the interactions and lets us calculate processes at very high precision. However, there are many questions that the Standard Model does not answer, e.g. cosmological data tell us that there is a lot of so-called "Dark Matter" in the Universe and the Nature of this Dark Matter is not yet understood within particle physics. Also, the fact that today there is only matter and no anti-matter in the Universe is as yet unexplained within particle physics. High energy accelerators create conditions that allow us to shed light on such phenomena. At high energies new particles may be produced that played an important role in the beginning of the Universe, such as e.g. Dark Matter particles.
Up to now the Tevatron accelerator near Chicago in Illinois has been the world's highest energy collider. I am a member of the CDF experiment which is a collaboration of about 700 scientist that has made many important observations and measurements in the recent and distant past. I joined the experiment in 2001 and was overall physics coordinator in 2005/2006. Among the recent highlights of the experiment are the precision measurement of the masses of the top quark and W boson, the observation of Bs meson oscillations and many other unique measurements that furthered the understanding of the strong and electroweak interactions and many searches for new particles that further constrain models of New Physics. However, to date no sign of new particles or interactions have been found.
The Large Hadron Collider (LHC) in Geneva in Switzerland will have an energy 7 times higher than any previous collider and take over as the world's highest energy accelerator. It is widely believed that it may revolutionize the field of particle physics by finding new species of particles and/or new laws of Nature. I recently joined the ATLAS experiment, one of the large experiments that will analyze the collisions at the LHC. The ATLAS experiment is a big enterprise and about 2000 scientists and many engineers and technicians are currently working on finishing the building of the experiment and understanding how to analyze its data. The experiments are also rather complex and indeed it takes so many physicists plus many technicians and engineers to construct and later operate these detectors. I am sure we are facing exciting times in the next few years when the first LHC data become available starting in 2008 and it is quite possible that a large number of new phenomena will be revealed.
CDF Collaboration (A. Abulencia et al.). “Observation of Exclusive Electron-Positron Production in Hadron-Hadron Collisions”,Phys.Rev.Lett.98,112001 (2007)
CDF Collaboration (A. Abulencia et al.), “Measurement of the b jet cross-section in events with a Z boson in p anti-p collisions at Ös = 1.96 TeV”, Phys.Rev.D 74,032008 (2006).
A. Bhatti, F. Canelli, B. Heinemann et al., “Determination of the jet energy scale at the collider detector at Fermilab”, Nucl. Instrum. Meth. A 566,375(2006).
CDF II Collaboration (D. Acosta et al.), “Measurement of W gamma and Z gamma production in p anti-p collisions at s**(1/2) = 1.96-TeV”, Phys. Rev. Lett. 94,041803 (2005).
H1 Collaboration (C. Adloff et al.). “Measurement of neutral and charged current cross-sections in electron - proton collisions at high Q2”, Eur. Phys. J. C 19, 269 (2001).
H1 collaboration (C. Adloff et al.) “Measurement of neutral and charged current cross-sections in positron proton collisions at large momentum transfer” Eur. Phys. J. C 13, 609 (2000).