ISSN:
1434-6052
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Using the ARGUS detector at DORIS, we have investigated the hadronic transitions of the Υ(2S) to the Υ(1S). The decays to Υ(1S)π+π−, Υ(1S)π0π0 and Υ(1S)η where the Υ(1S) subsequently decays intoe + e − and Υ(1S)η have been investigated. The transition via two charged pions has also been studied inclusively. We obtain branching ratios of the Υ(2S) into Υ(1S)π+π− of (18.1±0.5±1.0)%, into Υ(1S)π0π0 of (9.5±1.9±1.9)% and into Υ(1S)η of less than 0.5% with 90% confidence. From the exclusive events we find the leptonic branching ratios of the Υ(1S) to beB ee=(2.42±0.14±0.14)% andB μμ=(2.30±0.25±0.13)%. Kinematical parameters of the two pion transitions have been investigated in detail and found to be consistent with current algebra and colour-field multipole expansion.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01570762
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