Particle Dark Matter

The long-awaited Large Hadron Collider (LHC) is expected to start taking data in 2009. The LHC research programme has traditionally been centred around the discovery of the Higgs boson. However, the Standard Model description of this particle calls for New Physics. Until a few years ago, the epitome of this New Physics has been supersymmetry, which when endowed with a discrete symmetry called R-parity furnishes a good dark matter candidate. Recently a few alternatives have been put forward. Originally, they were confined to solving the Higgs problem, but it has been discovered that, generically, their most viable implementation (in accord with electroweak precision data, proton decay, etc.) fares far better if a discrete symmetry is embedded in the model. The discrete symmetry is behind the existence of a possible dark matter candidate.

From another viewpoint, stressed in many parts of this book, the past few years have witnessed spectacular advances in cosmology and astrophysics confirming that ordinary matter is a minute part of what constitutes the Universe at large. At the same time in which the LHC will be gathering data, a host of non-collider astrophysical and cosmological observations with ever-increasing accuracy will be carried out in search of dark matter. For example, the upcoming PLANCK experiment will make cosmology enter the era of precision measurements, akin to what we witnessed with the LEP experiments.

The emergence of this new paradigm means it is of utmost importance to analyse and combine data from these upcoming observations with those at the LHC.