  Motivated by the recent observation [Zeissler et al, Nature Comm. 11, 428
(2020)] of enigmatic radius-independent skyrmion Hall angle in chiral magnets,
we derive skyrmion Hall angle based on the recent solution of skyrmions
characterized by the sole length scale determined with the
Dzyaloshinskii-Moriya interaction strength and applied magnetic field. We find
that the skyrmion Hall angle is independent of input current density and the
length-scale which determines the radius of a skyrmion.This is corroborated
with the single length-scale dependent skyrmion profile which is the solution
of the Euler equation of polar angle representing magnetization. Although the
magnitude of Hall angle may change with the change of profile (shape) of the
skyrmion, it remains unchanged for a particular profile. With the application
of tunable current along mutually perpendicular directions, this property
enables us to propose an experimental setup by which the transverse motion of a
skyrmion can be restricted so that the skyrmion can only traverse
longitudinally. We further find the length-scale and input-current density
independent Hall angles for merons where their transverse motion will be
opposite depending on whether the spin at their centers are up or down, in
agreement with an experiment.
