arXiv subjects
Publications and source records attributed to N. I. Root.
We present a measurement of the pion form factor based on e+e- annihilation data from the CMD-2 detector in the energy range 0.6<sqrt(s)<1.0 GeV with a systematic uncertainty of 0.8%. A data sample is five times larger than that used in our previous measurement.
The cross section of the process e+e- -> pi+pi- has been measured at the CMD-2 detector in the 370-520 MeV center-of-mass (c.m.) energy range. A systematic uncertainty of the measurement is 0.7 %. Using all CMD-2 data on the pion form factor, the pion electromagnetic radius was calculated. The cross section of muon pair production was also determined.
The updated results of the precise measurements of the processes e+e-->rho->pi+pi-, e+e-->omega->pi+pi-pi0 and e+e-->phi->KLKS performed by the CMD-2 collaboration are presented. The update appeared necessary due an overestimate of the integrated luminosity in previous analyses.
The new parameterization of form factors developed for 4pi channels of the tau lepton decay and based on Novosibirsk data on e^+e^- -> 4pi has been coded in a form suitable for the TAUOLA Monte Carlo package. Comparison with results from TAUOLA using another parameterization, i.e. the CLEO version of 1998 is also included.
We demonstrate that a simple model successfully describing experimental data for the process $\epm\to 4π$ can also qualitatively account for the data of CLEOII and ALEPH obtained recently for the decay $τ\to 4πν_τ$. The model is based on the assumption of the $a_1(1260)π$ and $ωπ$ dominance as intermediate states. Our observation is in contrast with the claim by ARGUS that the $ρ$-meson signal in the $τ\to 4πν_τ$ decay can not be explained by the $a_1π$ intermediate state.