TESLA Brochure - ACFA Joint Linear Collider Physics and Detector ...

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Supersymmetry
Supersymmetry is a property ascribed to nature so
that the three forces of nature (the strong, electroweak
and gravitational interactions) can be unified
in a single “primal force.”It is therefore posited as
a fundamental property of nature. Supersymmetry
links the matter particles and force particles—which
are strictly separated in the Standard Model—by
stating that all particles are simultaneously both
one and the other. It also links the symmetries of
space-time with the “inner” symmetries associated
with the particle families—i.e. the intrinsic angular
momentum (spin) of the particles. For lower particle
energies, supersymmetry produces exactly the same
results as the Standard Model; unlike the latter,however,
it can also yield a reasonable description of the
very high particle energies found in the earliest
phases of the universe.
If nature is indeed supersymmetrical, there must
be twice as many kinds of particle as was previously
assumed. This is because supersymmetry requires
that for each and every “normal” type of particle,
there is also a corresponding “superpartner” type.
Consequently, there must be a whole range of new
and unusual types of matter. The problem is that as
long as none of these superpartner particle types are
detected, supersymmetry will remain an unproved
hypothesis. However, with the help of a linear electron-positron
accelerator running at sufficiently
high energies,it ought to be possible to generate and
identify at least some of these superpartner particles—provided,of
course,the theory is correct.
Understandably, the scientific interest in a project
of this nature is great. Supersymmetry would not
only provide physics with a new fundamental principle
of nature; it would also demonstrate that there
are new, unusual types of matter just waiting to be
discovered.