Wen-Tai Chiang

An isobar model for η photo- and electroproduction on the nucleon

An isobar model containing Born terms, vector meson exchange and nucleon resonances is used to analyze recent eta photoproduction data for cross section and beam asymmetry, as well as JLab electroproduction data. Good overall description is achieved up to Q^2 = 4.0 (GeV/c)^2. Besides the dominant S11(1535) resonance, we show that the second S11 resonance, S11(1650), is also necessary to be included in order to extract S11(1535) resonance parameters properly. In addition, the beam asymmetry data allow us to extract very small ( eta N decay branching ratios of D13(1520) and F15(1680) resonances because of the overwhelming s-wave dominance. The model is implemented as a part of the MAID program.

Magnetic dipole moment of the S11(1535) from the γp→γηp reaction

The \gamma p \to \gamma \eta p reaction in the S11(1535) resonance region is investigated as a method to access the S11(1535) magnetic dipole moment. To study the feasibility, we perform calculations of the \gamma p \to \gamma \eta p process within an effective Lagrangian approach containing both the S11 resonant mechanism and a background of non-resonant contributions. Predictions are made for the forthcoming experiments. In particular, we focus on the sensitivity of cross sections and photon asymmetries to the S11(1535) magnetic dipole moment.

Unitary model for the γ p → γ π 0 p reaction and the magnetic dipole moment of the Δ + ( 1232 )

Radiative pion photoproduction in the

Unitary model for the {gamma}p {yields} {gamma}{pi}{sup 0}p reaction and the magnetic dipole moment of the {Delta}{sup +}(1232)

\ensuremath{\Delta}(1232)

Magnetic moment of the S11 (1535) resonance

-resonance region is studied with the aim of accessing the

Probing the Magnetic Dipole Moment of the Delta+(1232) via gammap --> gammapi0p Reaction

{\ensuremath{\Delta}}^{+}(1232)

Unitary model for the γpγ°p reaction and the magnetic dipole moment of the δ{sup +}(1232)

magnetic dipole moment. We present a unitary model of the

Reggeized model for eta and eta' photoproduction

\ensuremath{\gamma}p\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\pi}N

Magnetic dipole moment of the S 11(1535) from the ?p? ??p reaction

(

Magnetic moment of the S 11 (1535) resonance

\ensuremath{\pi}N={\ensuremath{\pi}}^{0}p,\phantom{\rule{0.6em}{0ex}}{\ensuremath{\pi}}^{+}n