CHIRAL SCHWINGER MODEL WITH A PODOLSKY TERM AT FINITE-TEMPERATURE

We study an exactly solvable two-dimensional model which mimics the ba sic features of the standard model. This model combines chiral couplin g with an infrared behavior which resembles low energy QCD. This is do ne by adding a Podolsky higher-order derivative term in the gauge fiel d to the Lagrangian of the usual chiral Schwinger model. We adopt a fi nite temperature regularization procedure in order to calculate the no n-trivial fermionic Jacobian and obtain the photon and fermion propaga tors, first at zero temperature and then at finite temperature in the imaginary and real time formalisms. Both singular and non-singular cas es, corresponding to the choice of the regularization parameter, are t reated. In the nonsingular case there is a tachyonic mode as usual in a higher order derivative theory, however in the singular case there i s no tachyonic excitation in the spectrum.