The beam energy measurement system for the Beijing electron-positron collider

The beam energy measurement system (BEMS) for the upgraded Beijing electron-positron collider BEPC-II is described. The system is based on measuring the energies of Compton back-scattered photons. The relative systematic uncertainty of the electron and positron beam energy determination is estimated as 2 \cdot 10^{-5}. The relative uncertainty of the beam's energy spread is about 6 %

Measurement of the hadronic cross sections at Novosibirsk

Two experiments, CMD-3 and SND, collected over 100 pb−1 in total taking data in 2011-2013 at the VEPP-2000 electron-positron collider. The data sample covers the whole available c.m. energy range from 0.32 GeV to 2.0 GeV. An upgrade of VEPP-2000 started in the second half of 2013, aimed at the luminosity increase up to 10 times at 2.0 GeV. Data taking is expected to resumed in 2015. The current results of analysis of the collected data for various modes of e+ e− → hadrons are discussed

Precise measurements of the hadronic cross sections with the CMD-3 and SND detectors at the VEPP-2000

It’s good known the difference in 3.5 sigma between the muon (g – 2) experimental result and its calculation in Standard Model. To clarify this intriguing discrepancy the new stage of muon (g – 2) measurement is under preparation at Fermi National Laboratory. On other hand, regular data taking for measurements of hadron cross section production in e+ e− annihilations is under way since December 2010 at the electron-positron collider VEPP-2000 with the CMD-3 and SND detectors. The collected data sample corresponds to about 60 inverse picobarns of integrated luminosity per detector in the energy range from 0.32 up to 2 GeV. Preliminary analysis of various hadronic cross sections has been performed