（2＋1）—Dimensional Envelope Solitons in a Disk—Shaped Bose—Einstein Condensate

We show that, due to the nonlinear coupling between a wavepacket superposed by short-wavelength collective modes and a long-wavelength mean field generated by the self-interaction of the wavepacket, the (2 1)-dimensional envelope solitons decaying in all spatial directions, i.e., dromions, are possible nonlinear excitations in a disk-shaped Bose-Einstein condensate with a repulsive interatomic interaction.