LHC, here I come!

January 22, 2009

When the Large Hadron Collider (LHC) at CERN began operation last year, I wrote why so many particle physicists are excited about it. To be honest I really wasn’t one of them. See, the masters thesis I’m in the process of writing concerns a phenomenon simply unobservable at the LHC. However, I’ve decided that I shall be excited about the LHC from now on and therefore applied for a PhD scholarship programme. This programme might fund my researching things and stuff that will be observable at the LHC. How exciting!

Anyway, because it took me a long time to write and I’m pretty excited about it (see above), you now get to read my research proposal:

Distinguishing Between Models of New Physics at the LHC

Even though the Standard Model (SM) of Particle Physics is extremely successful in its experimentally confirmed predictions, it must be incomplete: it does not describe gravity, suffers from the hierarchy problem, provides no possibility for the unification of the forces, and lacks a dark matter candidate.

The most studied extension of the SM is Supersymmetry, but other models such as the Little Higgs Model, Randall-Sundrum models and Universal Extra Dimensions (UED) also provide solutions for some of these problems. In particular, even though their theoretical underpinnings differ greatly, all these models propose a range of new exotic particles of which the lightest stable one may serve as a dark matter candidate.

Discovering new physics beyond the Standard Model (BSM) by detecting such new particles is one of the main objectives of the Large Hadron Collider (LHC). Yet their mere detection would not assert which model was implemented by Nature. The goal of the proposed research project is to devise methods that allow one to distinguish between the different models based on phenomena observed at the LHC. This analysis will focus on cascade decays of heavy exotic particles into SM particles and other lighter exotic particles because we know from previous work that such decays allow the study of couplings, invariant mass hierarchies and spin correlations. These in turn are predicted by the various BSM models and therefore have discriminatory power.

Most previous studies on this subject only covered particular models and particular mass scenarios. For example, relevant works on Supersymmetry have focused on the Minimal Supersymmetric Standard Model (MSSM) and a particular parameter point (SPS 1a), neglecting not only other equally likely scenarios but other supersymmetric models as well. This research project therefore aims to improve on previous work by including models and scenarios favouring different mass hierarchies than the ones studied so far, with the ultimate goal of providing more refined means for distinguishing between BSM physics models at the LHC.

Now wish me luck. Please.

13 Responses to “LHC, here I come!”

  1. witsch Says:

    good luck! πŸ™‚

  2. Alex Clark Says:

    Good luck! Physics FTW! πŸ˜€

  3. Martijn Faassen Says:

    Good luck from me too!

    So which of these models should we be rooting for? Any of them offering goodies like faster than light travel or antigravity technology? Or of course the all important time travel, though faster than light travel could help us with that. πŸ™‚

  4. philikon Says:

    Thanks all for your good luck!

    Martijn: Well, I’m a SUSY (short for Supersymmetry) fan myself. It provides answers to many Standard Model problems, not just the dark matter thing. It does that by proposing another fundamental space-time symmetry (which ends up generating a whole slew of new particles). Particle theorists find that particular elegant. They love their symmetries.

    As for faster than light travel and all that, I’m afraid you’ll have to wait for the next Star Trek movie to come out πŸ™‚

  5. Godefroid Chapelle Says:

    Good luck to you Philipp.

    PHD implies you will still have time with the Zope community, right πŸ˜‰

  6. David Glick Says:

    Very cool…I got an undergrad degree in physics back before I got sucked into the Zope/Plone black hole… Have fun!

  7. Ed Eddington Says:

    Cool! I enjoy pondering such phenomena – but I, probably as David, spend way too much time pondering paradoxes in the strange universe of Zope/Plone!

  8. Raphael Ritz Says:

    Best wishes from me as well Philipp.

    Somehow this reminds me of the times when I had an interest in particle physics myself (not sure I could still write down the Lagrangian for the electro-weak interaction from the top of my head though …) but then I found biophysics to be more interesting even. Now – about 20 years later – I do what’s called Neuroinformatics (whatever that is) so things can evolve πŸ˜‰

    Good luck,


  9. Martin Says:

    Mmh, just read that the LHC won’t be up and running until 2010… So much for the “time for Zope” question πŸ™‚

  10. philikon Says:

    Martin, I’m a theorist so the LHC’s time out doesn’t really affect me (it actually gives the theorists more time to refine their calculations :)). I know the post’s title is a bit misleading… I’m not really going to work *at* the LHC (even if I make the scholarship programme).

  11. RobZoneNet Says:

    That is really cool man. Good Luck and Physics FTW!

  12. Darryl Noye Says:

    Congrats, and don’t shoot your eye out with that thing !

  13. Michael R. Bernstein Says:

    Congratulations, Philipp! BTW, you might enjoy reading ‘Flashforward’ by Robert J. Sawyer.

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