Berry’s phase for a spin 1/2 particle in the presence of topological defectsJosevi de S. Carvalho, E. Passos, Claudio Furtado and Fernando MoraesEur. Phys. J. C, 57 4 (2008) 817-822DOI: https://doi.org/10.1140/epjc/s10052-008-0696-1