TASSO was one of several experiments (CELLO, JADE, Mark-J,
PLUTO) which ran on the electron - positron collider PETRA at DESY in
Hamburg, Germany. The PETRA collider 
was approximately 1 km in
circumference and effectively surrounded the DESY laboratory.
Part of the rationale for PETRA was to search for new quarks, particularly the expected "top" quark. Earlier discoveries of the J/Psi ("charm" quark) and Upsilon ("bottom" quark) suggested that a sixth "top" quark should be close. The PETRA collider was ramped in centre of mass energies from 14 to 46 GeV and the various experiments, situated at the four interaction points of PETRA, looked for any new resonance or even a step in the ratio of hadrons produced to muons produced in the annihilation of the electron-positrons which would indicate a new quark. Unfortunately the "top" quark was much more massive than expected and was not seen at PETRA.
Nevertheless a great deal of very important physics was
discovered and studied at PETRA and TASSO, which started
operation in 1979, was an important part of those studies. The
most significant discovery at PETRA was that of three-jet events
which was he first experimental evidence for
gluons. Normally in electron-positron annihilations a quark and
anti-quark pair are produced which produce two jets of particles
into the detector. But when the energies of the quarks was
sufficiently high they could radiate a gluon as well resulting
in three jets. For this discovery P. Soeding, B. Wiik, G. Wolf,
and S.L. Wu were awarded the European
Physical Society Prize in High Energy and Particle Physics.
In addition to three jet events TASSO made numerous measurements on lifetimes and production cross sections for the new B and D mesons as well as a wealth of other topics.
The TASSO experiment was the first high energy experiment I worked on after my Ph.D. in 1983. It was a moderately large collaboration comprising approximately 100 physicists. I was based at the Rutherford Appleton Laboratory near Oxford, England and commuted to the experiment in Germany. But in fact I did rather little with TASSO other than run shifts and some studies on kaon and lambda production using the newly commissioned vertex detector. But the results were not significantly better than the previous results so no new publication came from it.
Most of my effort while at Rutherford was spent on the design and prototype studies for the central tracking detector planned for the ZEUS experiment and the electron-proton collider HERA. But that more properly falls under the link for ZEUS at the left.