RESUMO
The cross section of the process e^{+}e^{-}âπ^{+}π^{-} has been measured in the center-of-mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The measurement is based on an integrated luminosity of about 88 pb^{-1}, of which 62 pb^{-1} represent a complete dataset collected by CMD-3 at center-of-mass energies below 1 GeV. In the dominant region near the ρ resonance a systematic uncertainty of 0.7% was achieved. The implications of the presented results for the evaluation of the hadronic contribution to the anomalous magnetic moment of the muon are discussed.
RESUMO
One- and two-coordinate detectors with proportional chambers developed at the Budker Institute of Nuclear Physics (BINP) are presented. The parallax-free 10 MHz one-coordinate OD-3.1 and OD-3.2 detectors are used in synchrotron radiation powder diffraction and SAXS experiments. The two-coordinate DED-3 detector with a multiwire proportional chamber (MWPC) is used in Laue diffraction. The latest modification of this detector, DED-5, with a working area of 384 x 384 mm, is briefly described. The micro-strip detector prototype MSGC-100 has passed test synchrotron radiation experiments and the next modification (MSGC-500), with 500 channels for high energy, is under construction. The one-coordinate MWPC OD-160 detector, with an angle aperture of 160 degrees and a count rate of 3.3 GHz, is under construction. It will be used for high-resolution powder diffraction. Two types of gas chamber will be used: L for low energies (5-30 keV) and H for high energies (30-70 keV). A 16 degrees section with an H-chamber has been produced and tested on the synchrotron radiation beamline.
