We report on new H$(e,e^{\text{'}}p)\mathrm{<ruby><rb>\gamma </rb><rt>がんま</rt></ruby>}$ measurements in the $<ruby><rb>\Delta </rb><rt>でるた</rt></ruby>(1232)$ resonance at $Q^2=0.06$ (GeV/$c$)${}^2$ carried out simultaneously with H$(e,e^{\text{'}}p){\mathrm{<ruby><rb>\pi </rb><rt>ぱい</rt></ruby>}}^0$. It is the lowest $Q^2$ for which the virtual Compton scattering (VCS) reaction has been studied in the first resonance region. The VCS measured cross sections are well described by dispersion-relation calculations in which the multipole amplitudes derived from H$(e,e^{\text{'}}p){\mathrm{<ruby><rb>\pi </rb><rt>ぱい</rt></ruby>}}^0$ data are used as input, thus confirming the compatibility of the results. The derived resonant magnetic dipole amplitude $M_{1+}^{3/2}=(40.60\pm 0.{70}_{\mathrm{stat}+\mathrm{sys}})({10}^{-3}/m_{{\mathrm{<ruby><rb>\pi </rb><rt>ぱい</rt></ruby>}}^{+}})$ at $W=1232$ MeV is in excellent agreement with the value extracted from H$(e,e^{\text{'}}p){\mathrm{<ruby><rb>\pi </rb><rt>ぱい</rt></ruby>}}^0$ measurements.

• Received 6 April 2008

DOI:https://doi.org/10.1103/PhysRevC.78.018201