1 Erratum to: Eur. Phys. J. C (2015) 75:491 DOI 10.1140/epjc/s10052-015-3697-x

In Eqs. (11) and (12), replace \(2m_{12}^2\) with \(m_{12}^2\). The corrected equations read:

$$\begin{aligned} Y_1= & {} m_{11}^2c^2_\beta +m_{22}^2s^2_\beta -m_{12}^2 s_{2\beta }\cos \xi ,\end{aligned}$$
(11)
$$\begin{aligned} Y_2= & {} m_{11}^2s^2_\beta +m_{22}^2c^2_\beta +m_{12}^2 s_{2\beta }\cos \xi . \end{aligned}$$
(12)

At the end of the caption to Figure 2, the following sentence should be added: “Note that the constraints from Fig. 1 have not been imposed here.”