A particle of mass \(m\) is constrained to move along the positive \(x\)-axis under the influence of a conservative force associated with the potential energy function \(U(x) = \dfrac{a}{x^2} - \dfrac{b}{x}\), where \(a\) and \(b\) are positive constants.

The particle is released from rest at \(x = \dfrac{a}{b}\).

In terms of \(m\), \(a\), and \(b\), what is the maximum speed achieved by the particle during its subsequent motion?