We propose quantum dynamics for the dipole moving in cosmic string background and show that the classical scale symmetry of a particle moving in cosmic string background is still restored even in the presence of dipole moment of the particle. However, we show that the classical scale symmetry is broken due to inequivalent quantization of the nonrelativistic system. The consequence of this quantum anomaly is the formation of a bound state in the interval $\xi \in \left(-1,1\right)$. The inequivalent quantization is characterized by a one-parameter family of self-adjoint extension parameter $\Sigma$. We show that within the interval $\xi \in \left(-1,1\right)$, a cosmic string with zero radius can bind the dipole and the dipole does not fall into the singularity.

• Received 23 April 2007

DOI:https://doi.org/10.1103/PhysRevA.76.012114