Particle physics explores questions that are central to our understanding of the universe: What are we made of? What are the building blocks of our world and what holds them together? How did the universe come into existence and how did it become what it is today? DESY – the German acronym stands for German electron synchrotron – was founded as a national particle physics facility in 1959, in order to make it possible for scientists at German universities to study such questions. Today, DESY is one of the world’s leading research centres in this field.

50 years of particle research at DESY

Over the last 50 years, the results of particle physics research have revolutionized our understanding of the world. DESY has made major contributions to this progress. The research centre’s first outing on the international stage came in 1966, with precision measurements carried out using the first particle accelerator in Hamburg: the “Deutsches Elektronen-Synchrotron”, or DESY for short, the facility after which the research centre is named. These results made it possible to resolve an important controversy about the validity of quantum electrodynamics – the theory of the electromagnetic force – in favour of the theory.

In 1978, PETRA – at that time the largest storage ring of its type – was commissioned at DESY. Just one year later, the PETRA experiments made a groundbreaking discovery: for the first time ever, they were able to directly observe the gluon – the exchange particle of the strong force, which holds together the quarks, the fundamental building blocks of all matter.

Germany’s largest research instrument, the electron-proton accelerator HERA, was in operation at DESY from 1992 to 2007. The 6.3-kilometre-long super electron microscope provided physicists with the world’s sharpest view of the proton’s interior. Today many of the insights gained with HERA belong to our fundamental knowledge of how the world is put together. For many years to come, the evaluation of the HERA data will continue to provide unique insights into the inner structure of the proton and the fundamental forces of nature.

Particle research with a future

International cooperation across cultural and political boundaries enjoys a long tradition at DESY. DESY participates in a number of international facilities which are no longer supported by one country alone, but are instead realized as wide-ranging international projects. In particular, DESY is involved in the experiments at the world’s most powerful accelerator, the Large Hadron Collider LHC in Geneva, Switzerland. In addition, computing centres for monitoring LHC data acquisition and data analysis are being established at DESY.

DESY is playing a leading role in particle physics’ large future project, the planned International Linear Collider ILC. The ILC is based on the superconducting accelerator technology developed and tested by DESY and its international partners. This technology is also used in two facilities for photon science – the free-electron laser FLASH at DESY and the X-ray laser European XFEL, which is currently under construction. All these activities create important synergy effects that distinguish DESY as one of key research centres participating in the ILC.

The DESY researchers at the Zeuthen location are primarily active in the field of astroparticle physics. As part of their work in large international projects, they use various messengers from the cosmos – neutrinos and high-energy gamma rays – to uncover the secrets of stellar explosions, cosmic particle accelerators and dark matter. Projects in which the Zeuthen scientists are participating include the IceCube neutrino telescope at the South Pole and development work associated with the planned CTA gamma-ray telescope.

Even the best experiments don’t count for much without a solid theoretical foundation. DESY is a cornerstone of theoretical particle physics in Europe and worldwide. The DESY theory groups in Hamburg and Zeuthen study the underlying principles that explain the world of elementary particles and its physical laws. They explore the many facets of the Standard Model and aim to acquire new insights that embed the model into a unified theory of matter and forces – ideas which are of the highest interest in relation to the experiments at the LHC and the ILC.

In its role as the leading centre for particle physics in the Helmholtz Association, DESY initiated the Helmholtz Alliance “Physics at the Terascale” in 2007. The alliance brings together all of the German universities and institutes participating in the LHC and ILC. The objective is to focus and, in the long term, to enhance all of the expert knowledge of particle physics available in Germany. Within a short time, the alliance significantly improved the networking and international profile of particle physics in Germany – achievements that also helped to consolidate DESY’s position in the front ranks of particle physics.