Indeed, mathematically Barcelona still has that chance, but if no team succeeds in stopping Real Madrid until the end of the season then everything will be in vain. Apart from that, Real Madrid doesn't just need one defeat but at least four defeats if Barcelona wants to overtake them at the top of the standings. With that, it would be very impossible for Barcelona, but I have little faith that sometimes miracles do happen.
A miracle only happens if there are some certain clear facts of it happening, in this case, no miracle is happening and Barcelona cannot stop Real Madrid from winning the La Liga trophy. I feel they will be without trophy this season after missing on the La Liga title and also not much hope in them in the champions league because of the way they’re performing and the big teams in the competition who can easily evict them from the competition when they meet.