First Measurements of Timelike Form Factors of the Hyperons, Lambda0, Sigma0, Sigma+, Xi0, Xi-, and Omega-, and Evidence of Diquark Correlations

Abstract

Using 805 pb^-1 of e+e- annihilation data taken with the CLEO-c detector at psi(3770), sqrt{s}=3770 MeV, we report the first measurements of the electromagnetic form factors of the Lambda0, Sigma0, Sigma+, Xi0, Xi-, and Omega- hyperons for the large timelike momentum transfer of |Q^2|=14.2 GeV^2. The form factors for the different hyperons are found to vary by nearly a factor two. It is found that |G_M(Lambda0)|=1.66(24) x |G_M(Sigma0)|. The Lambda0 and Sigma0 hyperons have the same uds quark content, but differ in their isospin, and therefore the spin of the $ud$ quark pair. It is suggested that the spatial correlation implied by the singlet spin--isospin configuration in the Lambda0 is an example of strong diquark correlations in the Lambda0, as anticipated by Jaffe and Wilczek. Improved measurements of the branching fractions of psi(2S) -> p pbar and hyperon--antihyperon pairs are also reported.

arXiv comment5 pages, 4 figures

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Cited by in corpus (37)

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• Hyperon Form Factors & Diquark Correlations
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• Measurement of the cross section for $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ and evidence of the decay $\psi (3770)\to \Lambda \bar{\Lambda }$
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• Measurement of $\Lambda$ baryon polarization in $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ at $\sqrt{s}=3.773$ GeV
• Production and electromagnetic decay of hyperons: a feasibility study with HADES as a Phase-0 experiment at FAIR
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• Electromagnetic form factors of the ${\Omega }^{-}$ baryon in the spacelike and timelike regions
• The $\Sigma$ and $\Xi$ electromagnetic form factors in the extended vector meson dominance model
• Observation of $\psi (3686)\to n\bar{n}$ and improved measurement of $\psi (3686)\to p\bar{p}$
• Production and decay of polarized hyperon-antihyperon pairs
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• Radiative corrections for the decay ${\Sigma }^0\to \Lambda e^{+}{e}^{-}$
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• Symmetry analysis of charmonium two-body decay
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• Measurement of ${\Sigma }^{+}$ transverse polarization in $e^{+}{e}^{-}$ collisions at $\sqrt{s}=3.68-3.71$ GeV
• Search for Charmonium(-like) states decaying into the ${\Omega }^{-}{\bar{\Omega }}^{+}$ final states
• Chiral-odd generalized parton distributions for the low-lying octet baryons
• Observation of Transverse Polarization and Determination of Psionic Form Factors of the $\Lambda$ Hyperon at $\sqrt{s}=3.773$ GeV
• Observation of $\Xi (1530{)}^0$ Polarization and Determination of Its Electric and Magnetic Moments in $\psi (3686)\to \Xi (1530{)}^0\bar{\Xi }(1530{)}^0$
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