Having been successful in their search for the Higgs boson -- the so-called "God particle" that appeared to put a big red ribbon of completion on the Standard Model of physics -- you would think particle physicists would be happy to put their feet up on the couch and bask in the glow of their accomplishment. But no, they're off on a new hunt, this time for something called "supersymmetry."

Before we get into the mind-bending suppositions behind supersymmetry, a quick primer on the Higgs particle may be in order.

Proposed as a theory in 1964 and finally identified by scientists working at the CERN nuclear research facility in Europe in July 2012, the Higgs boson confirms the existence of the Higgs field, a critical addition to the Standard Model in explaining why fundamental particles have mass.

Under the Standard Model before Higgs, the symmetries of energy and force controlling their interactions should mean they would be without mass, which is contradicted everywhere we look in the universe.

Without mass, all the atoms created in the Big Bang would have simply floated around as the universe expanded, never coming together to form all matter known today. No galaxies, no stars, no solar systems with planets -- and no us.

So with the confirmation of the Higgs particle and field, and mass restored -- or rather explained -- why aren't particle physics happier than they seem to be?

The puzzlement is caused by the discovered mass of the Higgs boson itself -- which is much lighter than it should be, because interactions between it and all other Standard Model particles should make it heavy.

Enter supersymmetry, which suggests every particle we know about -- electrons, quarks, neutrinos and all the other inhabitants of the particle zoo -- has a corresponding superpartner of higher mass.

Those particles would interact through the same forces as in Standard-Model particles, and could cancel out the contributions to the Higgs mass from their Standard-Model partners, making a light Higgs boson -- apparently matching what was found at CERN -- possible.

If supersymmetric particles could be detected, it might also lead physicists to the Holy Grail of their field, a grand unified theory bringing together all the forces in the universe.

That's because if they exist, the interactions of the three Standard Model forces -- electromagnetism and the strong and weak nuclear forces -- could have the exact same strength at very high energies, as in the early universe.

A theory that unites the forces mathematically has been long-sought dream of physicists including Einstein.

And physicists with CERN are preparing for the new hunt.

They will spend most of this year upgrading the power of the Large Hadron Collider, the particle accelerator that revealed the Higgs.

Their aim is to increase the current 8 trillion electrovolts capability to 14 TeV to search for particles beyond the Higgs -- with supersymmetric particles in their sights.

And it's probably not accurate to say that physicists are unhappy with the current state of things in the particle world. New puzzles, a new theory and a new set of experiments are life-blood to science -- and scientists.

Let the hunt begin.