Observation of the Dynamic Beta Effect at CESR with CLEO

Abstract

Using the silicon strip detector of the CLEO experiment operating at the Cornell Electron-positron Storage Ring (CESR), we have observed that the horizontal size of the luminous region decreases in the presence of the beam-beam interaction from what is expected without the beam-beam interaction. The dependence on the bunch current agrees with the prediction of the dynamic beta effect. This is the first direct observation of the effect.

9 page uuencoded postscript file, postscritp file also available through http://w4.lns.cornell.edu/public/CLNS, submitted to Phys. Rev. E