Top-left: experimental cross sections from this work (black), along with theoretical calculations (see Sect. 7.1 for descriptions) and fits to them using Eq. (2) of Urdampilleta et al. (2017, solid lines). Bottom-left: ratios of the cross sections returned by the fitted curve to the calculated data points. The 1σ uncertainties on the experimental results are shown as dotted lines. Right: same but zoomed in on the low-energy region.