Scalar sigma meson at finite temperature in nonlocal quark model
  Properties and temperature behavior of pi and sigma bound states are studied in the framework of the nonlocal model with a separable interaction kernel based on the quark Dyson-Schwinger and the meson Bethe-Salpeter equations. M_pi(T), f_pi(T), M_sigma(T) and Gamma_{sigma -> pi pi}(T) are considered above and below the deconfinement and chiral restoration transitions. 
D. Blaschke, Yu. L. Kalinovsky, A. E. Radzhabov and M. K. Volkov