Humboldt-Universität zu Berlin - Faculty of Mathematics and Natural Sciences - Experimental Particle Physics

Collider Experiments

Large Hadron ColliderThe smallest consistuents of matter and their fundamental forces are explored in scattering experiments with particle beams.   For this, charged particles (electrons, protons & their antiparticles) are accelerated to very high energies by electric fields and brought to collision in huge accelerator facilities.  By measuring the final states of the particles' collisions precisely the physics of the microscopic interaction processes of the beam particles can be derived.  When particle-beams are kept after their acceleration for a longer time and are brought to collision again and again, the acceleration facility is called a storage ring or a collider.

The largest currently operating particle accelerator is the Large Hadron Collider (LHC) at CERN.  In this circular accelerator, protons are accelerated to an energy of up to 7 TeV and brought to collision at four collison points.  At each of these four points one huge experiment is located: ATLAS, CMS, LHCb and ALICE.

The two Experimental Elementary Particles Physics groups at Humboldt University Berlin participate in the ATLAS Experiment which is a large multi-purpose detector that is axialsymmetric to the proton beams.  The detector features the typical onion skin structure.  Near the interaction point of the proton beams the particles' tracks are measured and the bending in a magnetic field allows the determination of the momentum.  Afterwards, an energy measurement of the particles is carried out during which they partly or completely deposit their energy in the detector material.  In the outer layers of the detector, muons are measured because they are the only charged particles which are able to traverse the inner part of the detector without being absorbed.

Detectors | Cherenkov Telescopes | Collider Experiments | Neutrino Telescopes