Higgs Boson took the longest time to fit the standard model

We finally have this part of the Standard Model, the Higgs Boson discovered recently was the only missing part of the standard model. It took us almost 5 decades to discover Higgs Boson from the time it was theorized, it is the longest time taken by any of the standard model particles.
Here is the graph by The Economist showing how long it took us to find the particles of the standard model.