One end of a spring of negligible unstretched length and spring constant k is fixed at the origin (0,0). A point particle of mass m carrying a positive charge q is attached at its other end. The entire system is kept on a smooth horizontal surface. When a point dipole $\overrightarrow{\mathrm{p}}$ pointing towards the charge q is fixed at the origin, the spring gets stretched to a length l and attains a new equilibrium position (see figure below). If the point mass is now displaced slightly by Δl ≪ l from its equilibrium position and released, it is found to oscillate at frequency $\frac{1}{\mathrm{\delta }}\sqrt{\frac{\mathrm{k}}{\mathrm{m}}}$. The value of δ is ______.