Erratum to: Light-by-light scattering in a photon–photon collider

1 Erratum to: Eur. Phys. J. C (2018) 78:893 https://doi.org/10.1140/epjc/s10052-018-6364-1

In the published paper the cross-section for $\gamma \gamma \rightarrow \gamma \gamma$ was overestimated by a factor of 2. The number of events and statistical significance must be corrected. The factor is an overall coefficient of the cross section and is independent of center of energy or scattering angle. Therefore, the number of events $\gamma \gamma \rightarrow \gamma \gamma$ is reduced by half.

Page 4, the effective cross-section for the $\gamma \gamma \rightarrow \gamma \gamma$ and the expected number of events per second are corrected as;

$$\begin{aligned}&{\sigma _{eff}}(\gamma \gamma \rightarrow \gamma \gamma ) = 0.75\mu b\\&N_{sec}(\gamma \gamma \rightarrow \gamma \gamma ) = 1.4 \times 10^{-4} \end{aligned}$$

Page 6, statistical significance for the signals are corrected as;

$$\begin{aligned}&sig = \left\{ {\begin{array}{ll} 6.49 \pm 0.60&{}\quad \mathrm{{(0}}\mathrm{{.4nC,}}\;\mathrm{{2J)}}\\ 5.00 \pm 0.51&{}\quad \mathrm{{(2nC,}}\;\mathrm{{0}}\mathrm{{.4J)}} \end{array}} \right. \\&\begin{array}{c} 5.3< sig< 7.7\;\quad \mathrm{{(0}}\mathrm{{.4nC,}}\;\mathrm{{2J)}}\\ 4.0< sig < 6.0\;\quad \mathrm{{(2nC,}}\;\mathrm{{0}}\mathrm{{.4J)}} \end{array} \end{aligned}$$

In Table 2, the number of $\gamma \gamma \rightarrow \gamma \gamma$ events in the first column are corrected as;

$\gamma \gamma \rightarrow \gamma \gamma$
191.5 ± 1.4
182.0 ± 1.4

Figures 1, 8, 9, should be corrected accordingly, however, the difference from the published paper are virtually unnoticeable except for Fig. 9. We only show updated plot for Fig. 9.

Fig. 9

Expected statistical significance of $\gamma \gamma \rightarrow \gamma \gamma$ signal over the background after one year of operation for (0.4 nC, 2 J) (blue-solid), and (2 nC, 0.4 J) (purple-dashed)