Thursday, November 12, 2009

New Scientist on supersymmetry

Being the only blog on the planet Earth that actually expects supersymmetry to be seen at the LHC (more likely than not) and that has explained the reasons in many ways, The Reference Frame is pleased that Nude Socialist, a magazine dominated by crackpots most of the time, has published a sensible article explaining supersymmetry,
In SUSY we trust: What the LHC is really looking for.
Anil Ananthaswamy sketches some history of SUSY, the hierarchy problem, neutralinos as dark matter, gauge coupling unification, scenarios for the LHC results, and relationships between string theory and supersymmetry.

It is a solid introduction to the subject. One amusing misinterpretation does occur in the article: the author argues that the reason why confinement exists is only explained if supersymmetry exists. If you haven't recognized where this statement came from, it refers to the papers by Seiberg and Witten.

Well, confinement in N=2 theories has very good reasons and its properties may be analytically computed because of the enhanced supersymmetry. Things fit together - it is a beautiful calculation that showed how powerful supersymmetry is in simplifying calculations. But it is misleading to say that the "very existence" of confinement has to be explained by SUSY because we know theories, such as pure QCD, that are natural but still able to predict confinement.

By the way, I was once explained by a big shot theorist ;-) that Seiberg and Witten were thinking in terms of stringy objects and phenomena while they were writing the paper but they have erased all the references to string theory, apparently in order to extend their readership. However, this physical system was later naturally embedded in string theory and newer and crisper ways to calculate the results by stringy tools were found.

Even though there could have been a couple of additional readers that Seiberg and Witten have gained by this censorship of their mental processes, it's clear that the people who actually used the insights from the paper during the subsequent decade became contributors to the second superstring revolution.

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