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superpartner

n. (context physics English) Any particle related to a more standard particle by supersymmetry.

Wikipedia
Superpartner

In particle physics, a superpartner (also sparticle) is a hypothetical elementary particle. Supersymmetry is one of the synergistic theories in current high-energy physics that predicts the existence of these "shadow" particles.

The word sparticle features the s- prefix which is used to form names of superpartners of the individual fermions, e.g. the stop squark.

Usage examples of "superpartner".

The calculations that lead to the convergence of the force strengths, as well as other considerations studied by a number of physicists, indicate that the superpartner particles must be a good deal heavier than the known particles.

Instead, detailed theoretical analysis showed that if the universe incorporates supersymmetry, then every known particle must have an as-yet-undiscovered superpartner particle, whose spin is half a unit less than its known counterpart.

And finally, you might suggest that a simpler explanation for why the superpartner particles have never been found is that our universe is not supersymmetric and, therefore, the superpartners do not exist.

But many particle physicists feel that it means that the superpartners are very heavy and are thus beyond our current capacity to observe experimentally.

Conversely, even if superpartner particles are not found by the Large Hadron Collider, this fact alone will not rule out string theory, since it might be that the superpartners are so heavy that they are beyond the reach of this machine as well.