1 Erratum to: Eur. Phys. J. C (2018) 78:944 https://doi.org/10.1140/epjc/s10052-018-6415-7

Two typos in [1] are corrected.

  • The left-hand side of Eq. (43) should read \(Z_\chi ^{-1}\) instead of \(Z_\chi \).

  • The sign of the first term of the coefficient \(\gamma _{1,32}\) in Eq. (63) should be reversed. The correct coefficient reads

    $$\begin{aligned} \gamma _{1,32} = -\frac{272}{27} C_A T_F - \frac{392}{27} C_F T_F\,. \end{aligned}$$

Ancillary files for the paper can be found at arXiv:1808.09837.