@article{oai:ir.soken.ac.jp:00004780, author = {平田, 光司 and HIRATA, Koji and HIRATA, Kohji and KEIL, Eberhard}, issue = {1}, journal = {Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment}, month = {}, note = {The effects of the beam-beam interaction on the coherent motion of the barycentres of the colliding bunches are considered for asymmetric (two-ring) e+e− colliders, where circumference, energy, tune, etc. may be different between two rings. As well as integer and half-integer resonances, sum resonances occur. These resonances may be quite dense in the tune diagram, for the cases with different circumferences. This effectt poses a severe restriction on the choice of the circumference ratio. On these resonances, the beams separate spontaneously at the interaction point. In particular, on the sum resonance, the barycentres follow a limit cycle in four-dimensional phase space, rather than reaching a fixed point. This causes a severe drop in the luminosity. Results of analytical calculations and computer simulations for the motion of the barycentres and the excitation of the resonances are presented.}, pages = {156--168}, title = {Barycentre motion of beams due to beam-beam interaction in asymmetric ring colliders}, volume = {292}, year = {1990}, yomi = {ヒラタ, コウジ} }