M. N. Achasov

A system of beam energy measurement based on the Compton backscattered laser photons for the VEPP-2000 electron–positron collider

The beam energy measurement system for the VEPP-2000 electron-positron collider is described. The method of Compton backscattering of CO laser photons on the electron beam is used. The relative systematic uncertainty of the beam energy determination is estimated as 6 · 10. It was obtained through comparison of the results of the beam energy measurements using the Compton backscattering and resonance depolarization methods.

Energy calibration of the NaI(T1) calorimeter of the SND detector using cosmic muons

Abstract The general purpose spherical nonmagnetic detector (SND) is now taking data at VEPP-2M e+e− collider in BINP (Novosibirsk) in the center-of-mass-energy range of 0.2 – 1.4 GeV. The energy calibration of the NaI(Tl) calorimeter of the SND detector with cosmic muons is described. Using this method, the energy resolution of 5.5% (σ) for 500 MeV photons was achieved.The general purpose spherical nonmagnetic detector (SND) is now taking data at VEPP-2M

Study of e+e-→ωπ0→π0π0γ in the energy range 1.05-2.00 GeV with the SND detector

e^+e^-

Reanalysis of the e + e − → η γ reaction cross section

collider in BINP (Novosibirsk) in the centre of mass energy range of

The system for delivery of IR laser radiaton into high vacuum

0.2 \div 1.4

Direct measurement of the phi(1020) leptonic branching ratio.

GeV. The energy calibration of the NaI(Tl) calorimeter of the SND detector with cosmic muons is described. Using this method, the energy resolution of

Time resolution of the SND electromagnetic calorimeter

5.5 % (\sigma)

Study of the process e+e- → π+π -π0 in the energy region √s from 0.98 to 1.38 GeV

for 500 MeV photons was achieved.

Laser backscattering for beam energy calibration in collider experiments

The cross section for the process e+e- --> omega pi0 --> pi0 pi0 gamma has been measured in the energy range 1.05--2.00 GeV. The experiment has been performed at the e+e- collider VEPP-2000 with the SND detector. The measured e+e- --> omega pi0 cross section above 1.4 GeV is the most accurate to date. Below 1.4 GeV our data are in good agreement with the previous SND and CMD-2 measurements. Data on the e+e- --> omega pi0 cross section are well described by the VMD model with two excited rho-like states. From the measured cross section we have extracted the gamma^* --> omega pi0 transition form factor. It has been found that the VDM model cannot describe simultaneously our data and data obtained from the omega --> pi0 mu+ mu- decay. We have also tested CVC hypothesis comparing our results on the e+e- --> omega pi0 cross section with data on the tau- --> omega pi- nu_{tau} decay.

Measurement of hadron cross sections with the SND detector

In the experiment with the SND detector at the VEPP-2M