Gauge vortex dynamics at finite mass of bosonic fields

It is shown that the effective vortex dynamics resulting from an Abelian Higgs model is not necessarily governed by the Nambu-Goto action, provided the Higgs and vector boson masses are kept finite. This results in a slower contour motion characterized by the velocity suppressed, in the London limit, mainly as the ratio of the vector boson mass to its Higgs counterpart. The rate of the dissipationless helicity change is calculated. It is demonstrated how the conservation of the sum of the twisting and writhing numbers of the string is recovered despite the changing helicity.