Study of quantum mechanical scattering in presence of an extra compact   space dimension
  It is well known that string theory generates the idea of higher dimensional spacetime instead of the (3+1) dimensions, in which we seem to live. It indicates that the extra space dimensions may remain curled up into very small space. In this paper, we study quantum mechanical scattering in presence of extra compact space dimension in the hope of devising a method to get a clue to the presence of extra space dimension. We consider a simplified model of scattering, in which a beam of free particles is scattered due to a one dimensional Dirac-delta potential in presence of an extra compact space dimension. We find that the incident, reflected and transmitted probability current densities of the particles contain the information of the extra dimension. Thus, by measuring experimentally the reflected and transmitted probability current densities of the particles, we may confirm the presence of extra dimension. We also show that the idea of compactification of the extra dimensions gives rise to the quantization of the energy values of the free particles. So, by measuring the quantized energy values of the scattered free particles, we may again confirm the presence of extra dimensions. We also discuss briefly, how the extra compact space dimensions can be detected if the scattering process is performed in (9+1) dimensions, in which six space dimensions are compact. 
Ram Narayan Deb
quant-ph hep-th