ar X iv : c on d - m at / 9 81 13 81 v 1 2 6 N ov 1 99 8 Longitudinal and transverse forces on a vortex in superfluid 4 He

We examine the transverse and longitudinal components of the drag force upon a vortex filament due to the scattering of liquid 4He excitations. For this purpose, we consider a recently proposed Hamiltonian that describes the dissipative motion of a vortex, giving an explicit expression for the vortexquasiparticle interaction. The involved dissipative coefficients are obtained in terms of the reservoir correlation function. Most of our explicit calculations are concerned to the range of temperatures below 0.4 K, at which the reservoir is composed by phonon quasiparticle excitations. We also discuss some important implications in the determination of possible scattering processes leading to dissipation, according to the values of vortex mass found in the literature. PACS Numbers:67.40.Fd,05.40.+j,67.40.Vs,67.40.Db Typeset using REVTEX