The Higgs boson is lighter than the top quark. But the top quark was discovered in the mid-1990s where the Higgs boson escaped detection for two more decades. So if the energy has already been achieved to produce Higgs boson, why did it escape detection so far?
I understand that the couplings of Higgs boson to fermions is small and doesn't interact with the detector appreciably.
Does it mean that in LHC, with the increase in energy, the Higgs coupling increased and we finally detected Higgs?
With both particles you cannot detect them within their own lifetimes, only look at what they decay into. The top decays to a b jet and W (which can then become fermion anti-fermion or leptons) and is fairly distinctive. The dominant Higgs decay, however, is to two b jets. B jets are very common within the LHC and we cannot infer from two b jets that a Higgs detection has been made.
It's all about the statistics. With the top, its decay mode was distinctive enough that fewer events were needed before a statistically significant signal was seen above the background, whereas the Higgs needed many more events.
The Higgs being a scalar uncharged particle has the same quantum numbers as the vacuum, making it much harder to detect.
