Transverse Polarization of ${\Sigma }^{+}(1189)$ in Photoproduction on a Hydrogen Target in CLAS

Abstract

Experimental results on the ${\Sigma }^{+}(1189)$ hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson laboratory are presented. The ${\Sigma }^{+}(1189)$ was reconstructed in the exclusive reaction $\gamma +p\to K_S^0+{\Sigma }^{+}(1189)$ via the ${\Sigma }^{+}\to p{\pi }^0$ decay mode. The $K_S^0$ was reconstructed in the invariant mass of two oppositely charged pions with the ${\pi }^0$ identified in the missing mass of the detected $p{\pi }^{+}{\pi }^{-}$ final state. Experimental data were collected in the photon energy range $E_{\gamma }$ = 1.0-3.5 GeV ($\sqrt{s}$ range 1.66-2.73 GeV). We observe a large negative polarization of up to 95%. As the mechanism of transverse polarization of hyperons produced in unpolarized photoproduction experiments is still not well understood, these results will help to distinguish between different theoretical models on hyperon production and provide valuable information for the searches of missing baryon resonances.

arXiv commentpages 11

References in corpus (14)

• Quasi-Two-Body Decays of Nonstrange Baryons
• Differential Cross Sections for gamma + p --> K+ + Y for Lambda and Sigma0 Hyperons
• Measurement of gamma p --> K+ Lambda and gamma p --> K+ Sigma0 at photon energies up to 2.6 GeV
• Hyperon Photoproduction in the Nucleon Resonance Region
• Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab
• First Measurement of Beam-Recoil Observables Cx and Cz in Hyperon Photoproduction
• Measurement of the reaction gamma p --> K0 Sigma+ at photon energies up to 2.6 GeV
• Differential cross sections and recoil polarizations for the reaction gamma p -> K+ Sigma0
• First Measurement of Transferred Polarization in the Exclusive e p --> e' K+ Lambda Reaction
• Pion- and photo-induced transition amplitudes to $\Lambda K$, $\Sigma K$, and $N\eta$
• Beam-Recoil Polarization Transfer in the Nucleon Resonance Region in the Exclusive $\vec{e}p\to e^{\prime }{K}^{+}\vec{\Lambda }$ and $\vec{e}p\to e^{\prime }{K}^{+}{\vec{\Sigma }}^0$ Reactions at CLAS
• Nucleon resonances in the fourth resonance region
• New Baryons in the Delta eta and Delta omega Channels
• Polarization in Hyperon Photo- and Electro- Production

Cited by in corpus (4)

• Light Baryon Spectroscopy
• Light baryon resonances from a coupled-channel study including $\mathbf{K\Sigma }$ photoproduction
• Sign ambiguity in the K Sigma channel
• Measurement of polarisation observables in $K_s^0{\Sigma }^{+}$ photoproduction off the proton