Kook-Jin Kong

Nondiffractive feature of γN→ρ±N with ρ-meson electromagnetic multipole moments

Abstract We investigate photoproduction of charged ρ off the nucleon using ρ ( 770 ) + π ( 140 ) Regge pole exchanges by considering the ρ -meson electromagnetic multipole moments. The significance of the Ward identity at the γρρ vertex is emphasized for current conservation in the process. Given π exchange with the well-known coupling constants for γπρ and πNN , we analyze the role of the ρ exchange in the γ p → ρ + n and γ n → ρ − p processes without model-dependences except for the magnetic moment μ ρ ± = ± 2.01 and electric quadrupole moment Q ρ ± = ± 0.027 fm 2 taken from theoretical estimates. The nondiffractive feature of both cross sections is reproduced with a rapid decrease beyond the resonance region by the dominance of π exchange over the ρ . Cross sections for differential and density matrix elements are presented to compare with existing data. The parity and photon polarization asymmetries are predicted to demonstrate the apparent roles of the ρ -meson electromagnetic multipole moments.

Investigating convergence of the reaction γp → π±Δ and tensor meson a2 exchange at high energy

Abstract A Regge approach to the reaction processes γ p → π − Δ + + and γ p → π + Δ 0 is presented for the description of existing data up to E γ = 16 GeV . The model consists of the t-channel π ( 139 ) + ρ ( 775 ) + a 2 ( 1320 ) exchanges which are reggeized from the relevant Born amplitude. Discussion is given on the minimal gauge prescription for the π exchange to render convergent the divergence of the u-channel Δ-pole in the former process. A new Lagrangian is constructed for the a 2 N Δ coupling in this work and applied to the process for the first time with the coupling constant deduced from the duality plus vector dominance. It is shown that, while the π exchange dominates over the process, the role of the a 2 exchange is crucial rather than the ρ in reproducing the cross sections for total, differential, and photon polarization asymmetry to agree with data at high energy.

Investigating convergence of the reaction

Abstract A Regge approach to the reaction processes γ p → π − Δ + + and γ p → π + Δ 0 is presented for the description of existing data up to E γ = 16 GeV . The model consists of the t-channel π ( 139 ) + ρ ( 775 ) + a 2 ( 1320 ) exchanges which are reggeized from the relevant Born amplitude. Discussion is given on the minimal gauge prescription for the π exchange to render convergent the divergence of the u-channel Δ-pole in the former process. A new Lagrangian is constructed for the a 2 N Δ coupling in this work and applied to the process for the first time with the coupling constant deduced from the duality plus vector dominance. It is shown that, while the π exchange dominates over the process, the role of the a 2 exchange is crucial rather than the ρ in reproducing the cross sections for total, differential, and photon polarization asymmetry to agree with data at high energy.

\gamma p\to\pi^\pm\Delta

We investigate the role driven by the scalar meson

with tensor meson

\sigma

a_2

exchange in the photoproduction of the vector meson

exchange at high energy

\phi

Role of

(1020) off a proton by using a Reggeized model. Based on the

\sigma

\pi^0(135)+\sigma(500)+f_2(1270)

exchange in the

+Pomeron exchanges, we demonstrate that the