GlueX Physics

Photoproduction

• Experimental Papers
  • Differential cross sections and spin density matrix elements for γp → ω p, M. Williams, et al., (CLAS Collaboration), submitted to Phys. Rev. C (2009), arXiv.
  • Partial wave analysis of γ p → ω p and the search for nucleon resonances, M. Williams, et al., (CLAS Collaboration), submitted to Phys. Rev. C (2009), arXiv.
  • Differential cross sections for the reactions γ p → η p and γ p → η' p, M. Williams, et al., (CLAS Collaboration), submitted to Phys. Rev. C (2009), arXiv.
  • On the Analysis of Vector-Meson Production by Polarized Photons,K. Schilling, P. Seyboth and G. Wolf, Nucl. Phys. B15 (1970), 397-412, pdf
  • Bubble-Chamber Study of Photoproduction by 2.8 and 4.7 GeV Polarized Photons. I. Cross-Section Determination and Production of ρ⁰ and Δ⁺⁺ in the Reaction γp → pπ+π- J. Ballam et al., Phys. Rev. D5 (1972), 545-589, pdf.
  • Vector-Meson Production by Polarized Photons at 2.8, 4.7 and 9.3 GeV, J. Ballam et al., Phys. Rev. D7 (1973), 3150-3177, pdf.
  • Spin-Parity Analysis of ρ' in the reaction γ p → π+ π+ π- π-p at 9 to 18 GeV, Joseph C.H. Park, Nucl. Phys. B58, (1973), 45-54, pdf.
  • High-Energy Production and Decay of vector and Tensor Mesons, A.C. Irving and C. Michel, Nucl. Phys. B82, (1974), 282-325, pdf.
  • The Reaction γ p → π+ π- π+ π- p at High-energy and dissociation into 4π, M. Davier, et al., Nucl. Phys. B58 (1973), 31-44, pdf.

Strong Decay Models

Attempts at modeling strong decays date from 1969, when Micu suggested that hadron decay proceeds through $q\bar q$ pair production with vacuum quantum numbers, $J^{{PC}}=0^{{++}}$. Since this corresponds to a ³P₀ $q{\bar q}$ state, it is now generally referred to as the 3p0 decay model. This suggestion was developed and applied extensively by Le Yaouanc et al. in the 1970s. Studies of hadron decays using the 3p0 model have been concerned almost exclusively with numerical predictions, and have not led to any fundamental modifications to the original model. Recent studies have considered changes in the spatial dependence of the pair production amplitude as a function of quark coordinates but the fundamental decay mechanism is usually not addressed; this is widely believed to be a nonperturbative process, involving ``flux tube breaking". There have been some studies of the decay mechanism which consider an alternative phenomenological model in which the $q{\bar q}$ pair is produced with ³S₁ quantum numbers; this possibility however appears to disagree with experiment.

• mesons
  • Higher quarkonia, T.Barnes, F.E. Close, P.R. Page and E.S. Swanson, Phys. Rev. D55 (1997), 4157-4188 PRD.
  • On the mechanism of open flavor strong decays, E.S. Ackleh, T. Barnes and E.S. Swanson, Phys. Rev. D54 (1996), 6811-6829, PRD.
  • Hybrid and conventional mesons in the flux tube model: Numerical studies and their phenomenological implications, T. Barnes, F.E. Close and E.S. Swanson, Phys. Rev. D52 (1995), 5242-5256, PRD.
  • The Quenched Approximation In The Quark Model, P. Geiger and N. Isgur, Phys. Rev. D41 (1990), 1595, PRD.
  • Meson Decays by Flux Tube Breaking, R. Kokoski and N. Isgur, Phys. Rev. D35 (1987), 907, PRD.
  • A Flux Tube Model for Hadrons in QCD, N. Isgur, J. E. Paton, Phys. Rev. D31 (1985), 2910, PRD.
  • A Flux Tube Model for Hadrons N. Isgur and J. E. Paton, Phys. Lett. B124, (1983), 247, Science Direct.
• hybrids
  • The "forbidden" decays of hybrid mesons to π ρ can be large, F.E. Close and J.J. Dudek, Phys. Rev. D70 (2004), 094015, arXiv.
  • Hybrid Meson Decay Phenomenology, P.R. Page, E.S. Swanson and A.P. Szczepaniak, Phys. Rev. D59 (1999), 034016, arXiv.
  • Why Hybrid Meson Coupling to Two S-wave Mesons is Suppressed, P.R. Page, Phys. Lett. B402 (1996), 183-188, arXiv.
  • Q anti-Q G Hermaphrodite Mesons in the MIT Bag Model, T. Barnes, F.E. Close, F. de Viron and J. Weyers, Nucl. Phys. B224 (1983), 241, Science Direct.
  • Gluonic Excitations of Mesons: Why They Are Missing and Where to Find Them, N. Isgur, R. Kokoski and J. E. Paton, Phys. Rev. Lett. 54 (1985), 869, PRL.