Finite temperature meson correlation functions in HTL approximation

We calculate temporal correlators and their spectral functions with meson q uantum numbers in the deconfined phase of QCD using the hard thermal loop ( HTL) approximation for the quark propagator. Although this approach does no t result in a complete next-to-leading order perturbative calculation it ta kes into account important medium effects such as thermal quark masses and Landau damping in the quark-gluon plasma. We show that both effects lead to competing modifications of the free mesonic correlation functions. We find that correlators in scalar channels are only moderately influenced by the HTL medium effects, while the HTL-vertex corrections lead to divergent vect or correlators. (C) 2001 Elsevier Science B.V. All rights reserved.