Is Nature Supersymmetric?

[abacus9900]

Unifying all the known forces in physics into a single theory would require that two very different kinds of particles are closely related, an idea called 'supersymmetry.'

The first, fermions, are the building blocks of matter, like protons, electrons and neutrons. Bosons, on the other hand, are force carriers such, as for example, photons, the conveyors of light. The concept of supersymmetry requires that every fermion would have a boson twin, and vice-versa. These 'super-partners' are termed 'sparticles' so that for the electron there would exist the 'selectron', for the photon the 'photino.'

Sparticles have not been observed in nature so why has the perfect symmetry that must have existed at the BB been broken?

[speakertoanimals]

Sparticles have not been observed in nature so why has the perfect symmetry that must have existed at the BB been broken?

We already have example, in the standard model, of broken symmetries. The massive W and Z bosons (which mediate the weak force), have been unified with the massless photons that mediates the em force in the electroweak theory. This symmetry is spontaneously broken, giving massless photons and the large-scale em forces, plus massive W and Z, and very short-range and weak weak force!

This symmetry breaking behaviour is actually quite common in physics. Consider a set of little magnetic dipoles, without an external field. There is no preferred direction (no external field), yet dipoles interact and under right conditions, will all align in one particular direction. By so doing, they spontaneously break the original rotational symmetry (no preferred direction becomes preferred direction being the one they are aligned along). Related ideas link to spontaneous symmetry breaking in particle physics.

[abacus9900]

[buckleymanor1]

Sparticles have not been observed in nature so why has the perfect symmetry that must have existed at the BB been broken?

It might be that if perfect symmetry prevailed then nothing would exist.If perfect symmetry had not broke at the BB you would have had equal amounts of matter and anti-matter, which would have annihilated each other leaving nothing.

[principled]

STA

massless photons

Ok, these photons have energy but no mass. Now under E=MC^2 we calculate the energy contained by mass lost x constant that happens to be c^2? Correct? So, if something is massless, how does one calculate the energy it has?
P

[nickcosmosonde]

Well, now you're just being difficult.