• Question: What do you think about the theory of supersymmetry, and is it likely that dark matter is a sparticle?

    Asked by doppler to Adam, Geoff, Rob, Sheila, Suzie on 17 Mar 2011 in Categories: .
    • Photo: Suzie Sheehy

      Suzie Sheehy answered on 16 Mar 2011:

      Great question, you’ve obviously done a lot of reading!

      I like the theory of supersymmetry as it is quite elegant. I think it makes sense to have a family of particles that are almost the exact opposites of the ones we have already but heavier. It solves a lot of problems with our current theories. But at the end of the day, it’s just a theory… so do we have any evidence for it?

      Interestingly, the results from the Large Hadron Collider are already telling us new things about this theory – at least it’s telling us which parts of if might not be true. We haven’t found and sparticles yet but keep reading the news, because we might!

      As for whether it’s “likely” that dark matter is a sparticle I’m not sure. Supersymmetry predicts particles called neutralinos which are a good candidate for dark matter, but there are other candidates as well. As I said, it’s a nice idea but we just can’t tell how nature really works until we do experiments!

      I hope that the Large Hadron Collider will be able to tell us!

      EDIT: Thanks to Tom Whyntie for correcting my previous answer, the neutralino isn’t just the supersymmetric partner of the neutrino! My memory failed me on this one!

    • Photo: Geoff McBride

      Geoff McBride answered on 16 Mar 2011:

      This came up yesterday over coffee with a scientist that is experimenting with atomic clocks on the International Space Station. He measures the difference between clocks on the Space Station compared to thos one Earth. We both agreed that Dark Matter is worrying and that we both felt that something was very wrong with the current theory. But what is it!

    • Photo: Adam Tuff

      Adam Tuff answered on 16 Mar 2011:

      Personally, we haven’t seen any evidence for supersymmetry so I’m sceptical! But as they say, “absence of proof is not proof of absence”. It would solve something called the Heirarchy problem, which is basically also related to why the Higgs Boson mass (the “God” particle they are looking for at the Large Hardon Collider) is so small. Supersymmetry is definitely a very nice way, but as an experimentalist, I’d like to see some evidence!

      Dark matter could well be a sparticle – it could be caused by neutrinos if they have a large enough mass, or they could even be a type of super-dense astronomical object, like say a quark star, that we haven’t observed yet.

      A really, really good question doppler – can I ask the name of your school and your teacher?

    • Photo: Sheila Kanani

      Sheila Kanani answered on 17 Mar 2011:

      Great question!

      At the moment there is no evidence for supersymmetry but that doesn’t mean it doesn’t exist, and I like the idea that every boson has a corresponding fermion. Means no one will ever get lonely 😉

      If supersymmetry were to exist is could provide a candidate for dark matter in terms of an sparticle yes.

      I think you have exhausted my knowledge of this topic, well done! 🙂

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