The Standard Model of particle physics does a great job of explaining how the Universe is put together around us, but it doesn’t explain everything.
The idea of supersymmetry fills in the holes of the Standard Model, and it is the only known mathematical symmetry that can be added to the symmetries of Einstein’s Theory of Relativity without producing equations inconsistent with the known Universe.
There are two types of the most basic particles known to man. Fermions are the particles primarily responsible for providing mass and bosons are the particles responsible for the force interactions in the Universe.
Supersymmetry says every single fermion and boson has one or more superpartners, such that the superpartner of any fermion is a boson and vice versa. However, known particles don’t have the theoretical properties of superpartner. This means that for every known particle, there is a currently-unknown particle that is its superpartner. Superpartners have identical interactions with other particles and identical masses.
Despite the fact that we haven’t discovered these superpartner particles, that hasn’t stopped particle physicists from naming them. For bosons, photon has a photino, gluons have gluinos, Higgs have Higgsinos and so on. Fermions have much, much more complicated names.
These superpartners don’t exist in the world as we know it, and acknowledging their presence at this point would highly complicate the world of chemistry. For instance, if the superpartner for an electron, a selectron, with the same charge and mass, were to exist, it would mean considering atoms with electrons as well as atoms with selectrons. This would throw the periodic table into chaos as it would mean countless new kinds of atoms.
So what is the point of all this then, if supersymmetry can’t exist in world? Why bother adding it to Einstein’s symmetries and set up a naming system?
According to theory, supersymmetry does exist, it is just hidden from our view. Calculations have shown that if the superpartners of all known particles are extremely heavy, too heavy for scientists to have generated them in the lab. However, the Large Hadron Collider at CERN in Switzerland is expected, based on calculations, to produce superpartners.
Researchers at the massive international particle physics project did have a major breakthrough with respect to supersymmetry when they confirmed the existence of the Higgs boson in 2013.
Calculations had determined that Higgs should be a very light particle. However, studies have also found interactions with known particles make Higgs very heavy. Supersymmetry, with its very heavy superpartners, solves this problem – allowing for Higgs to be very light.
As for the lightest superpartner, scientists have predicted it to be steady, electrically neutral and to interact weakly with known particles. These are precisely the characteristics essential for dark matter, thought to make up most of the matter in the universe and to hold galaxies together.
The Standard Model by itself does not supply an explanation for dark matter. Supersymmetry is a construction that builds upon the Standard Model’s strong basis to develop a more vibrant picture of our world. Maybe the reason we still have many of these questions on intricacies of the universe is due to the fact we have only seen one half of the picture.