$E2\mathrm{/}M1$ Ratio for the $\gamma N\to \mathrm{\Delta }$ Transition in the Chiral Quark Soliton Model

We calculate the electric quadrupole to magnetic dipole transition ratio $E2\mathrm{/}M1$ for the reaction $\gamma N\text{ra}\mathrm{\Delta }(1232)$ in the chiral quark soliton model. The calculated $E2\mathrm{/}M1$ ratio is in a good agreement with the very new experimental data. We obtain non-zero negative value for the electric quadrupole $N-\mathrm{\Delta }$ transition moment, which suggests an oblate deformed charge structure of the nucleon or/and the delta isobar. Other observables related to this quantity, namely the $N-\mathrm{\Delta }$ mass splitting, the isovector charge radius, and isovector magnetic moment, are properly reproduced as well.