Let the equation of the circle, which touches $x$-axis at the point $(a,0)$, $a>0$, and cuts off an intercept of length $b$ on $y$-axis be $x^{2}+y^{2}-\alpha x+\beta y+\gamma=0$. If the circle lies below $x$-axis, then the ordered pair $(2a,,b^{2})$ is equal to