Measurement of $\Lambda$ transverse polarization in $e^{+}{e}^{-}$ collisions at $\sqrt{s}=3.68-3.71$ GeV

Abstract

With data samples collected with the BESIII detector at seven energy points at $\sqrt{s}=3.68-3.71$ GeV, corresponding to an integrated luminosity of 333 pb${}^{-1}$, we present a study of the $\Lambda$ transverse polarization in the $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$ reaction. The significance of polarization by combining the seven energy points is found to be 2.6$\sigma$ including the systematic uncertainty, which implies a non-zero phase between the transition amplitudes of the $\Lambda \bar{\Lambda }$ helicity states. The modulus ratio and the relative phase of EM-$psionic$ form factors combined with all energy points are measured to be $R^{\Psi }=$ 0.71${}_{-0.10}^{+0.10}$ $\pm$ 0.03 and $\Delta {\Phi }^{\Psi }$ = (23${}_{-8.0}^{+8.8}$ $\pm$ 1.6${)}^{\circ }$, where the first uncertainties are statistical and the second systematic.

19 pages, 4 figures, 3 tables, consistent with the publication in JHEP10(2023)081 and JHEP12(2023)080 (erratum)

References in corpus (8)

• Dispersion analysis of the nucleon form factors including meson continua
• Method for detector description transformation to Unity and application in BESIII
• Leading SU(3)-breaking corrections to the baryon magnetic moments in Chiral Perturbation Theory
• Nucleon electromagnetic form factors from lattice QCD using a nearly physical pion mass
• Hyperon Form Factors & Diquark Correlations
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• Probing the internal structure of baryons
• Predicted $\Lambda \bar{\Lambda }$ and ${\Xi }^{-}{\bar{\Xi }}^{+}$ decay modes of the charmoniumlike $Y(4230)$

Cited by in corpus (5)

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• Production and decay of hyperons in a transversely polarized electron-positron collider
• Measurement of Born cross section of $e^{+}{e}^{-}\to {\Sigma }^0{\bar{\Sigma }}^0$ at $\sqrt{s}=3.50-4.95$ GeV
• 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 $\psi (3686)\to \Xi (1530{)}^0\bar{\Xi }(1530{)}^0$