A dynamical mass generation of a two-component fermion in the Maxwell-Chern-Simons QED3: The lowest ladder approximation

A dynamical mass generation of a two-component fermion in QED3 with the Chern-Simons term is investigated by solving the Schwinger-Dyson equation formulated in the lowest ladder approximation. Dependence of the dynamical fermion mass on the gauge-fixing parameter, the gauge coupling constant, and the topological mass is examined by approximated analytical and also numerical methods. The inclusion of the Chern-Simons term makes impossible to choose a peculiar gauge in which the wave function renormalization is absent. The numerical evaluation shows that the wave function renormalization is fairly close to 1 in the Landau gauge. It means that this gauge is still a specific gauge where the Ward-Takahashi identity is satisfied approximately. We also find that the dynamical mass is almost independent of the topological mass in a parameter region adopted here, while the dynamical mass decreases very slightly when the topological mass is comparable to or smaller than the coupling constant. It seems that the amount of parity breaking due to the Chern-Simons term in the gauge sector affects the dynamical mass generation in the fermion sector in a non-trivial way. e-mail address: [email protected] 0