Observation of e+e- --> rho+rho- near sqrt(s)=10.58 GeV

The BABAR Collaboration; B. Aubert

doi:10.1103/PhysRevD.78.071103

paper

Observation of e+e- --> rho+rho- near sqrt(s)=10.58 GeV

arXiv:0806.3893 · doi:10.1103/PhysRevD.78.071103

Abstract

We report the first observation of $e^{+} e^{-} \to ρ^{+} ρ^{-}$ , in a data sample of 379 $f b^{- 1}$ collected with the BABAR detector at the {PEP-II} $e^{+} e^{-}$ storage ring at center-of-mass energies near $s = 10.58 G e V . W e m e a s u r e a cr osssec t i o n o f$ σ({e^+e^-\} \to ρ^+ ρ^-) = {19.5 \pm 1.6(stat) \pm 3.2(syst) fb} $. A ss u min g p r o d u c t i o n t h r o ug h s in g l e - p h o t o nannihi l a t i o n, t h er e a r e t h r ee in d e p e n d e n t h e l i c i t y am pl i t u d es . W e m e a s u r e t h er a t i oso f t h e i r s q u a r e d m o d u l i t o b e$ |{F}_{00}|^2 : |{F}_{10}|^2 : |{F}_{11}|^2 = 0.51 \pm 0.14(stat) \pm 0.07(syst) : 0.10 \pm 0.04(stat) \pm 0.01(syst) : 0.04 \pm 0.03(stat) \pm 0.01(syst) $. T h e$ |{F}_{00}|^2$ result is inconsistent with the prediction of 1.0 made by QCD models with a significance of 3.1 standard deviations including systematic uncertainties.

8 pages, 4 postscript figures, submitted to PRD-RC