Collaboration with DESY

(German Electron Synchrotron Lab)

The HERA at DESY in Hamburg, Germany is the first electron-proton collider in the world. It collides a proton beam of 920 GeV with an electron or positron beam of 27.6 GeV. The e-p collision can be regarded as an extreme extension of what electron microscopes do; one probes the target with 'light' emitted from the electron enabling to look at the size as short as one thousandth of a proton radius. At such scale, one sees quarks and gluons in the proton, and their dynamical behavior. If the quarks are not the ultimate elementary particle, one would perhaps see their substructure - subquarks.

KEK has been participating in one of the two HERA collider experiments, ZEUS, with Tokyo Metropolitan and other Japanese Universities since its beginning. It consists of 450 physicists from 12 countries. Japan shares responsibility for its first-level trigger, uranium-scintillator calorimeter, hadron-electron separator and recently in forward- plug calorimeter and microvertex detector which is to be installed next year.

Carrying out a long-run experiment abroad requires creative thinking to solve many problems. One must deal with occasional hardware problems in DESY even when one is back to Japan, with remote diagnostics over the network. Video conferencing is extensively used in analysis team across several countries. We also have to deal with difference in fiscal-year period between Europe and Japan especially on budgeting.

The life at DESY is very international and fun. The International Office in DESY makes life much easier for people from abroad. Starting from September 2000, HERA will undergo a major upgrade to increase the luminosity (the rate of particle collisions) by a factor of five. We look forward to the new data-taking of upgraded HERA from 2001, which gives us substantial increase in the physics potential.

		The author of this article, Dr. Masahiro KUZE, has been participating in ZEUS since 1990 and is coordinating its physics group for the searches for physics beyond the Standard Model.