Correlator of the quark scalar currents and $Γ_{tot}(H \to hadrons)$ at $ O (α_s^3^3)$ in pQCD

We present the results of the analytical evaluation of the massless four-loop ${\cal O}(\as^3)$ correction to the correlator of the quark scalar currents and the Higgs decay rate into hadrons. In numerical form we found (in MS-bar scheme) that $ \Gamma(H \to \bar{b} {b}) = \frac{3G_F}{4\sqrt{2}\pi}M_H m_b^2(M_H) [1 + 5.667 \alpha_s/\pi + (35.94 - 1.359 n_f\right)(\alpha_s/\pi)^2 +(164.139 - 25.771n_f + 0.259 n_f^2)(\alpha_s/\pi)^3\right] $ where $n_f$ is the number of quark favours and $\alpha_s = \alpha_s(M_H)$.