Search

The γp→ηp reaction has been measured with the Crystal Ball and TAPS multiphoton spectrometers in the energy range from the production threshold to 1.4 GeV (1.49≤W≤1.87 GeV). Bremsstrahlung photons produced by the 1.5-GeV electron beam of the Mainz Microtron MAMI-C and momentum analyzed by the Glasgow Tagging Spectrometer were used for the η-meson production. Our accumulation of 3.8×106 γp→ηp→3π0p→6γp events allows a detailed study of the reaction dynamics. The γp→ηp differential cross sections were determined for 120 energy bins and the full range of the production angles. Our data show a dip near W = 1680 MeV in the total cross section related to a substantial dip in η production at forward angles. The data are compared to predictions of previous SAID and MAID partial-wave analyses and to the latest SAID and MAID fits that included our data. [ABSTRACT FROM AUTHOR]

Cascade hyperons have two special characteristics, which are particularly valuable as experimental and theoretical tools: cascades have strangeness minus two and their widths are quite narrow compared to the N* and Δ+ resonances. The narrow width allows the detection by the missing mass or invariant mass techniques. The makeup of the cascade states is two “massive” strange and one light quark, this makes them much more amendable to Lattice Gauge calculations. Using the well established Flavor Symmetry of QCD we can use a comparison of the Cascades with the N* and Δ* resonances to make a conclusive search for the “Unseen Resonances” of the quark model, for Hybrid Baryons, Meson-Baryon Bound States and other Exotica. We can investigate the flavor dependence of confinement: is the string tension between two strange quarks the same as between two down quarks? © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]