Particle physics at DESY

All over the world, scientists strive to answer the key questions of the origin and nature of our universe. However, it will only be possible to make headway here if everyone involved joins together in national and international research networks. This networking – across political and cultural borders – enjoys a long tradition at the particle physics research centre DESY.

DESY – An international centre for particle and astroparticle physics

The construction of the HERA accelerator at DESY in the 1980s was a prime example of successful international cooperation. A total of 11 countries collaborated to realize the project, financing more than 20 per cent of the accelerator and more than 60 percent of the HERA experiments. This “HERA model” of international cooperation worked so well that it became a role model for carrying out large international research projects.

This long-term international networking continues to benefit DESY after HERA has been switched off. As in astronomy, where researchers from all over the world work with a few telescopes constructed and operated in international collaboration, the focus of particle physics is shifting to a few large-scale facilities that can no longer be sustained by one country alone, but can only be realized in wide-ranging international cooperation.

The particle physicists at DESY contribute their knowledge at various such large-scale, international facilities: the particle accelerators LHC and ILC, the neutrino telescope IceCube and the gamma-ray telescope CTA. This leads to new forms of cooperation both on the national and international level.

The main topics of particle research at DESY

HERA

Using data recorded with the “super electron microscope” HERA, particle physicists investigate the structure of the proton and the fundamental forces of nature.

For 15 years, electrons and protons collided inside the 6.3-kilometre-long HERA particle accelerator, which lies deep in the earth beneath Hamburg. Data taking at Germany’s largest research instrument, which has written physics history, ended in the summer of 2007. The evaluation of the recorded measurement data, however, which will take some more years, will give us a comprehensive overall picture of the proton and the forces at work inside it.

LHC

DESY is also playing a part in work at today’s most powerful accelerator worldwide: the new Large Hadron Collider LHC at CERN in Geneva, Switzerland.

In the LHC, protons collide at energies of 14 teraelectronvolts, i.e. 14 trillion electronvolts – the highest energies ever attained in a particle accelerator. The LHC will enable physicists to venture far into the uncharted territories of the terascale. With the help of its particle collisions, the physicists hope to find answers to a wide range of unresolved questions in current particle theory. The insights into the proton provided by HERA are an indispensable basis for their work.

ILC

The discoveries at the LHC can only be fully comprehended in conjunction with an electron-positron accelerator whose unique precision will enable physicists to reveal the secrets of the terascale in all their facets.

One such big project planned for the future is the International Linear Collider ILC – an approximately 35-kilometre-long linear accelerator in which electrons and their antiparticles, the positrons, will collide at energies of 500 to around 1000 billion electronvolts. DESY is a major participant in this accelerator of the future, whose concept is based on the superconducting accelerator technology developed at DESY.

IceCube and CTA

DESY is active in astroparticle physics at its location in Zeuthen, Germany. The DESY researchers use various particles – messengers from the cosmos – to uncover the secrets of stellar explosions, cosmic particle accelerators and dark matter.

DESY is a major participant in the international neutrino telescope IceCube, which has been frozen deep into the ice of the South Pole. With its volume of one cubic kilometre, it is the world’s largest particle detector. In the future, the scientists will also be hunting for high-energy electromagnetic radiation from outer space with the planned gamma-ray telescope CTA.

Theory

Theoretical particle physics strives to piece together the big picture that underlies all the various experimental results.

In order to explain the world of elementary particles and the laws of physics that rule it, the theorists at DESY use numerous mathematical tools and high-performance computers developed especially for this purpose. Only by working closely together are theorists and experimentalists able to penetrate the mysteries of nature and – so the scientists hope – to ultimately work out a comprehensive theory of all particles and forces.