Determination of the ${\Sigma }^{+}$ Timelike Electromagnetic Form Factors

Abstract

Based on data samples collected with the BESIII detector at the BEPCII collider, the process $e^{+}{e}^{-}\to {\Sigma }^{+}{\bar{\Sigma }}^{-}$ is studied at center-of-mass energies $\sqrt{s}$ = 2.3960, 2.6454, and 2.9000 GeV. Using a fully differential angular description of the final state particles, both the relative magnitude and phase information of the ${\Sigma }^{+}$ electromagnetic form factors in the timelike region are extracted. The relative phase between the electric and magnetic form factors is determined to be $\sin \Delta \Phi$ = -0.67~$\pm$~0.29~(stat)~$\pm$~0.18~(syst) at $\sqrt{s}$ = 2.3960 GeV, $\Delta \Phi$ = 55${}^{\circ }$~$\pm$~19${}^{\circ }$~(stat) $\pm$~14${}^{\circ }$~(syst) at $\sqrt{s}$ = 2.6454 GeV, and 78${}^{\circ }$~$\pm$~22${}^{\circ }$~(stat) $\pm$~9${}^{\circ }$~(syst) at $\sqrt{s}$ = 2.9000 GeV. For the first time, the phase of the hyperon electromagnetic form factors is explored in a wide range of four-momentum transfer. The evolution of the phase along with four-momentum transfer is an important input for understanding its asymptotic behavior and the dynamics of baryons.

References in corpus (14)

• Baryons as relativistic three-quark bound states
• High-precision determination of the electric and magnetic form factors of the proton
• 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
• Measurement of the proton form factor by studying $e^{+}{e}^{-}\to p\bar{p}$
• Study of the process $e^{+}{e}^{-}\to n\bar{n}$ at the VEPP-2000 $e^{+}{e}^{-}$ collider with the SND detector
• Nucleon Electromagnetic Form Factors in the Timelike Region
• ${\Sigma }^{+}$ and ${\bar{\Sigma }}^{-}$ polarization in the $J/\psi$ and $\psi (3686)$ decays
• Octet baryon electromagnetic form factors in nuclear medium
• Measurement of the cross section for $e^{+}{e}^{-}\to {\Xi }^{-}{\bar{\Xi }}^{+}$ and observation of an excited $\Xi$ baryon
• Hyperon electromagnetic form factors in the timelike region
• Electromagnetic form factors of neutron and neutral stange hyperons in the oscillating view of point
• Study of $e^{+}{e}^{-}\to {\Sigma }^0\overline{\Sigma }{}^0$ and ${\Sigma }^{+}\overline{\Sigma }{}^{-}$ by Initial State Radiation Method at Belle
• Dispersion-theoretical analysis of the electromagnetic form factors of the $\Lambda$ hyperon

Cited by in corpus (5)

• Unraveling the structure of $\Lambda$ hyperons with polarized $\Lambda \bar{\Lambda }$ pairs
• 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 $\psi (3686)\to \Xi (1530{)}^0\bar{\Xi }(1530{)}^0$
• Time-like electromagnetic form factors of $\Lambda ,\Sigma$ and ${\Xi }^{+}$ in a light-front quark model
• Accessing baryon-antibaryon generalized distribution amplitudes in $e^{\pm }\gamma \to e^{\pm }B\bar{B}$