Вы находитесь на старом сайте НГУ. Перейти на новый сайт

ISSN - 01709739, Zeitschrift f�r Physik C-Particles and Fields, 1992, vol. 54, p. 229-234

Measurement of the branching ratio for Υ(1 S) state into π+π- andsearch for decays Υ(1 S)→π+π-, K+K-, p {Mathematical expression}

Baru S. E., Beilin M. V., Blinov A. E., Blinov V. E., Bondar A. E., Bukin A. D., Groshev V. R., Klimenko S. G., Kolachev G. M., Onuchin A. P., Panin V. S., Protopopov I. Ya, Shamov A. G., Sidorov V. A., Skovpen Yu I., Skrinsky A. N., Tayursky V. A., Telnov V. I., Tikhonov Yu A., Tumaikin G. M., Undrus A. E., Vorobiov A. I., Zilich V. N.

In the experiment with e+e--beams performed at the VEPP-4 storage ring with the MD-1 detector we have measured Bμμ, the branching ratio for the decay of Υ(1 S) state into μ+μ-. We obtained Bμμ=(2.12+0.20+0.10)%. It is shown that the continuum and resonance interference should be taken into account. For the first time the upper limits on the branching ratio for the decays Υ→π+π-, K+K-, p {Mathematical expression} have been measured: Br(Υ→π+π-)<5·10-4, Br(Υ→K+K-)<5·10-4, Br(Υ→p {Mathematical expression}<9·10-4 (90% CL). © 1992 Springer-Verlag.