First Operational Experience with DORIS II
DORIS II is a completely new designed e+-e- storage ring with a mini-beta scheme. After first runs with a 8 cm optic, the vertical amplitude functions in the interaction points were reduced to 4 cm. This yielded luminosities of L = 1.5 . l031 cm-2sec-1 with 2 × 27 mA at E = 5 GeV. Because of the short injection time, an integrated luminosity of more than 600 nb-1 per day has been obtained.
Synchrotron radiation facilities at DESY, a status report
Abstract A short summary of the developments which have led to the present extensive use of Synchrotron Radiation at DESY is presented and a description of the Synchrotron Radiation facilities presently available and under development is given with emphasis on the new HASYLAB project at the storage ring DORIS.
Ypsilons and Jets at DORIS
The production of the Y(9.46)- and Y'(10.02)-resonances in e+e--annihilation has been observed in three, respectively two, different experiments at DORIS. The observed leptonic decay widths are consistent with Y and Y' being the ground and the first excited state of a bound b system, where b represents a heavy quark with charge - 1/3. The event topology at energies outside the Y resonances clearly exhibit 2-jet structure in good agreement with the quark parton model. The characteristics of the Y direct hadronic decays are consistent with the 3 gluon model.