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.