  The formation of novel dynamical states for a collection of dust particles in
two dimensions has been shown with the help of Molecular Dynamics (MD)
simulation. The charged dust particles interact with each other with Yukawa
pair potential mimicking the screening due to plasma. Additionally, an external
radial confining force has also been applied to the dust particles to keep them
radially confined. When the particle number is low ( say a few), they get
arranged on the radial location corresponding to multiple rings/shells. For
specific numbers, such an arrangement of particles is stationary. However, for
several cases, the cluster of dust particles relaxes to a state for which the
dust particles on rings display inter-shell rotation. For a larger number of
dust particles ( a few hundred for instance ) a novel equilibrium state with
coherent rigid body displaying angular oscillation of the entire cluster is
observed. A detailed characterization of the formation of these states in terms
of particle number, coupling parameter, etc., has been provided.
