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Thursday, February 25, 2016

What is Super symmetry (SUSY)? How does it relate to the Standard Model?

Easy and concise explanation!

The Standard Model in Particle Physics so far explains the building blocks of the Universe and the force carriers. But it is 'incomplete'. Supersymmetry is an extension of the SM that aims to fill some of the gaps. It predicts a partner particle for each particle in the Standard Model. These new particles would solve a major problem with the Standard Model – fixing the mass of the Higgs boson.

It is still a mystery why the Higgs boson should be light, as interactions between it and Standard-Model particles would tend to make it very heavy.

The extra particles predicted by supersymmetry would cancel out the contributions to the Higgs mass from their Standard-Model partners, making a light Higgs boson possible. The new particles would interact through the same forces as Standard-Model particles, but they would have different masses. If we consider supersymmetry then the three 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 is called a grand unified theory, which is the aim of all the theoretical Physicists.

SUSY would also link the two different classes of particles known as fermions (half unit spin) and bosons (integral spin). SUSY predicts that each of the particles in the Standard Model has a partner with a spin that differs by half of a unit. Hence, this idea can bring these two groups together.

[Image: How the complete picture might look like after supersymmetry consideration]