6533b870fe1ef96bd12cfac5

RESEARCH PRODUCT

The Reactionγp→π0γ′pand the Magnetic Dipole Moment of theΔ+(1232)Resonance

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description

The reaction $\ensuremath{\gamma}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{\ensuremath{\gamma}}^{\ensuremath{'}}p$ has been measured with the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI for energies between $\sqrt{s}=1221--1331\text{ }\text{ }\mathrm{M}\mathrm{e}\mathrm{V}$. The cross section's differential in angle and energy have been determined for the photon ${\ensuremath{\gamma}}^{\ensuremath{'}}$ in three bins of the excitation energy. This reaction channel provides access to the magnetic dipole moment of the ${\ensuremath{\Delta}}^{+}(1232)$ resonance and, for the first time, a value of ${\ensuremath{\mu}}_{{\ensuremath{\Delta}}^{+}}=\mathbf{[}{2.7}_{\ensuremath{-}1.3}^{+1.0}(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t})\ifmmode\pm\else\textpm\fi{}1.5(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\ifmmode\pm\else\textpm\fi{}3(\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{o}\mathrm{r})\mathbf{]}{\ensuremath{\mu}}_{N}$ has been extracted.