Dong, SH (reprint author), Inst High Energy Phys, Beijing 100039, Peoples R China.
In this Letter the bound states of (2+1) Dirac equation with the cylindrically symmetric delta(r - r(0)) potential are discussed. It is surprisingly found that the relation between the radial functions at two sides of r(0) can be established by an SO(2) transformation. We obtain a transcendental equation for calculating the energy of the bound state from the matching condition in the configuration space. The condition for existence of bound states is determined by the Sturm-Liouville theorem.