Observation of $e^{+}{e}^{-}$ Annihilations into the $\boldmath{C=+1}$ Hadronic Final States ${\rho }^0{\rho }^0$ and $\varphi {\rho }^0$

Abstract

We report the first observation of $e^{+}{e}^{-}$ annihilations into states of positive $C$-parity, namely ${\rho }^0{\rho }^0$ and $\varphi {\rho }^0$. The two states are observed in the $\pip\pim\pip\pim$ and $K^+K^-\pip\pim$ final states, respectively, in a data sample of 225~$f{b}^{-1}$ collected by the $BaBar$~experiment at the $PEP-II$ $e^{+}{e}^{-}$ storage rings at energies near $\sqrt{s}=$ 10.58~$GeV$. The distributions of $\cos {\theta }^{\ast }$, where ${\theta }^{\ast }$ is the center-of-mass polar angle of the $\varphi$ meson or the forward ${\rho }^0$ meson, suggest production by two-virtual-photon annihilation. We measure cross sections within the range $|\cos {\theta }^{\ast }|<0.8$ of $σ(\e^+e^- \to ρ^0 ρ^0) ~=~$$20.7\pm 0.7(\mathrm{stat})\pm 2.7(\mathrm{syst})\mathrm{fb}$ and $σ(\e^+e^- \to ϕρ^0) \~=~$$5.7\pm 0.5(\mathrm{stat})\pm 0.8(\mathrm{syst})\mathrm{fb}$.

7 pages, 6 postscript figues, submitted to Physical Review Letter

References in corpus (3)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• The BABAR Detector
• Updated Estimate of the Muon Magnetic Moment Using Revised Results from e+e- Annihilation

Cited by in corpus (6)

• Search for new charmonium states in the processes e+ e- --> J/psi D(*) D(*) at sqrt{s} ~ 10.6 GeV
• Exclusive Two-Vector-Meson Production from e^+ e^- Annihilation
• Search for direct production of the $f_1(1285)$ resonance in $e^{+}{e}^{-}$ collisions
• Observation of e+e- --> rho+rho- near sqrt(s)=10.58 GeV
• Observation of the Exclusive Reaction e+e- -> phi eta at sqrt{s}=10.58 GeV
• Cross sections of e+e- --> gamma VV and e+e- --> gamma gamma V