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 $$\overrightarrow{p}$$ 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 $$\triangle l << l$$ from its equilibrium position and released, it is found to oscillate at frequency $$\frac{1}{\delta}\sqrt{\frac{k}{m}}$$. The value of $$\delta$$ is ______.