Neutron helicity amplitudes

The helicity amplitudes for the photoproduction of nucleon resonances excited from neutrons are determined in the Bonn-Gatchina coupled-channel partial wave analysis. Upper limits for the decay fraction of the pentaquark candidate $N\left(1685\right)\to K^0\mathrm{\Lambda }$ are given. The electric and magnetic couplings at the pole positions are also tabulated, and these are used to suggest candidates for possible multiplets with quark-spin-1/2 and -3/2 content.

Figure 1

Left: Differential cross sections for $\gamma d\to K^0\mathrm{\Lambda }\left(p\right)$. Red squares and black circles represent data from the CLAS g10 and CLAS g13 runs, respectively [20]. Right: $\gamma d\to K^{+}{\mathrm{\Sigma }}^{-}\left(p\right)$ [22]. The solid and dashed curves show two BnGa fits.

Figure 2

$E$ asymmetry for $\vec{\gamma }\vec{n}\to {\pi }^{-}p$ in bins of the invariant mass [21]. The solid and dashed curves show two BnGa fits.

Figure 3

Total cross sections for $\gamma d\to K^0\mathrm{\Lambda }\left(p\right)$ [20] and $\gamma d\to K^{+}{\mathrm{\Sigma }}^{-}\left(p\right)$ [22]. The contributions from three major partial waves with $I=1/2$ and $J^P=1/2^{\pm }$ and $3/2^{+}$ for the two major fits are also shown. Red squares and black circles represent data from the CLAS g10 and CLAS g13 experimental runs, respectively. Open and solid symbols represent the two fit results (see text).

Figure 4

The $\gamma d\to \eta n\left(p\right)$ excitation curve for the angular range $0.8<cos\theta <0.9$ from the data from Refs. [15, 16] (open circles, $0.8<cos\theta <0.9$) and from Ref. [24] (black dots, $0.8<cos\theta <1$). The solid and dashed curves show the two BnGa fits, which include the data from Refs. [15, 16] but not the data from Ref. [24].