Sparticles

[Zarnaxus]

I have heard that the higher vibration of superstings or something of the sort can cause normal matter and particles to become sparticles. right? I really dont have much of an idea on these strange particles. sprotons and... sneutrons (hahah)? And, is there a possibility that along with sparticles comes anti-sparticles as well? Explicame!

[timo]

There is an extension of the space-time symmetries which is called "supersymmetry", or SUSY for short. If SUSY exists in nature, then for every elementary particle, a similar particle, a superpartner, must exist. The elementary particles currently known are not superparter to another, so if SUSY exists, quite a lot of yet-unknown particles must exist. These superpartners of known particles are called sparticles (and also the superpartner of say the electron is the selectron). SUSY is by far the most prominent model for exotic physics, i.e. extensions of the Standard Model of Particle Physics. It is not the same as superstring theory. String theory is often considered to need SUSY, but SUSY does not require string theory, and is more general.

And yes, the relation particle <-> anti-particle also holds for sparticle <-> anti-sparticle. People don't speak of sprotons or sneutrons, though. Those are not elementary particles, and an object being composed of squarks and gluinos (sometimes, the superpartner is labeled with an ending -ino instead of a leading s), provided it could exist, is not likely to resemble a neutron or a proton.

Edited December 17, 2010 by timo

[Zarnaxus]

I have also read that nature could have created three "generations" of particles. one being the normal stuff that we know so very well, the ... supersymmetric version of those elementary particles, and now, what is this third generation if there is one? is it antimatter?

 

 

[ajb]

I have also read that nature could have created three "generations" of particles. one being the normal stuff that we know so very well, the ... supersymmetric version of those elementary particles, and now, what is this third generation if there is one? is it antimatter?

 

Have a quick read of the wikipedia article on the standard model.

 

The standard model does not say why there are three generations. I don't think there is any really convincing mechanism or theory saying why.

 

String theory is often considered to need SUSY, but SUSY does not require string theory, and is more general.

 

I remember asking John Ellis about this. The answer was

 

``String theory needs supersymmetry more than supersymmetry needs string theory ``

 

 

Which is true. Any realistic or phenomenologically interesting string theory needs to be supersymmetric, but there are well defined point-particle theoreis that have supersymmetry. Interestingly, a version of supersymmetric Yang-Mills theory is finite and does not require renormalisation (other than wave-function renormalisation). SUSY can have some great mathematical properties that are very useful in physics.