the existence of longer and more intense current sheets: for smaller $\beta$, the length of the blue and green isocontours of the current density in the vicinity of the null point increases. In addition, for smaller $\beta$, one observes that some black field lines are open, whereas they initially belonged to the closed domain. Furthermore, we observe in Fig. \[Fig:BetaE\] that the lower-$\beta$ curves of the free magnetic energy present a slightly more gentle slope, an indication of the magnetic dissipation occurring at the reconnection site. This demonstrates that relatively more reconnection has occurred at $t/t_0=625$ for the runs with smaller $\beta$, even though the driving is the same.

By analyzing the moment at which the intense current sheet appears (not shown here), we find that the lower the $\beta$, the earlier the current sheet forms at the 3D null point, and the more intense is the reconnection when it develops. This indicates that the lower the plasma $\beta$, the earlier and the stronger is the reconnection during the [[straight jet]{}]{}phase. However, in our low-$\beta$ simulations, this more intense reconnection does not result in the formation of a more marked high-density region and extended upflows that would be interpreted as 