Study of $e^{+} e^{-} \to \Lambda \bar{\Lambda}$, $\Lambda \bar{\Sigma}^0$, $\Sigma^0 \bar{\Sigma}^0$ using initial state radiation with BABAR

We study the e+e- --> Lambda anti-Lambda gamma, Lambda anti-Sigma0 gamma, Sigma0 anti-Sigma0 gamma processes using 230 fb-1 of integrated luminosity collected by the BABAR detector at e+e- center-of-mass energy of 10.58 GeV. From the analysis of the baryon-antibaryon mass spectra the cross sections for e+e- --> Lambda anti-Lambda, Lambda anti-Sigma0, Sigma0 anti-Sigma0 are measured in the dibaryon mass range from threshold up to 3 GeV/c^2. The ratio of electric and magnetic form factors, |G_E/G_M|, is measured for e+e- --> Lambda anti-Lambda, and limits on the relative phase between Lambda form factors are obtained. We also measure the J/psi --> Lambda anti-Lambda, Sigma0 anti-Sigma0 and psi(2S) --> Lambda anti-Lambda branching fractions.

Note:

24 pages, 37 postscript figures, submitted to Phys. Rev. D

13.66.Bc
13.25.Gv
13.40.Gp
14.20.Jn
electron positron: colliding beams
electron positron: annihilation
hyperon: pair production
Lambda: electroproduction
Sigma0: electroproduction
radiation: initial-state interaction

References(25)

Figures(0)

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