Radiative $\varphi$ decays with derivative interactions

We study the line shapes of radiative $\varphi$-decays involving virtual $f_0(980)$ and $a_0(980)$ mesons which decay, via derivative couplings, to ${\pi }^0{\pi }^0$ and ${\pi }^0\eta$ respectively. After developing the formalism for derivative interactions at one-loop level, we show that they can reproduce the measured peaked line shapes of $\varphi$-decays without including kaon loops.