Spectrum of the heavy axial vector \chi_b1(1P) and \chi_c1(1P) mesons in   thermal QCD
  Using the additional operators coming up at finite temperature, we calculate the masses and decay constants of the P wave heavy axial-vector \chi_b1 and \chi_c1 quarkonia in the framework of thermal QCD sum rules. In the calculations, we take into account the perturbative two loop order alpha_s corrections and nonperturbative effects up to the dimension four condensates. It is observed that the masses and decay constants almost remain unchanged with respect to the variation of the temperature up to T \simeq 100 MeV, however after this point, the decay constants decrease sharply and approach approximately to zero at critical temperature. The decreasing in values of the masses is also considerable after T \simeq 100 MeV . 
E. Veli Veliev, K. Azizi, H. Sundu, G. Kaya
hep-ph