120 research outputs found
Study of the process e+e-\to \mu+\mu- in the energy region \sqrt{s}=980, 1040 -- 1380 MeV
The cross section of the process e+e-\to\mu+\mu- was measured in the SND
experiment at the VEPP-2M e+e- collider in the energy region \sqrt{s}=980, 1040
-- 1380 MeV. The event numbers of the process e+e-\to\mu+\mu- were normalized
to the integrated luminosity measured using e+e-\to e+e- and
e+e-\to\gamma\gamma processes. The ratio of the measured cross section to the
theoretically predicted value is 1.006\pm 0.007 \pm 0.016 and 1.005 \pm 0.007
\pm 0.018 in the first and second case respectively. Using results of the
measurements, the electromagnetic running coupling constant \alpha in the
energy region \sqrt{s}=1040 -- 1380 MeV was obtained = 134.1\pm 0.5
\pm 1.2 and this is in agreement with theoretical expectation.Comment: 29 pages, 23 figure
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