In the first few lectures, we take a whistlestop tour of current and recent facilities for ee, ep and pp collisions. There are many other interesting particle physics experiments going on in the world, both searching for new physics at the energy frontier and making precision tests of theory at lower energies. It would probably be possible to fill an entire lecture module with them!

In place of two lectures where I am absent, you are invited here privately to look into two further classes of experiment which are of high current interest: studies of heavy ion collisions and of neutrino oscillations. There is a wealth of information available on the web in both areas (a google search will get you a long way). Below are a few pointers to the main current experiments.

In particular, please look for answers to the following broad questions:

  • Which basic physics questions are the facilities built to address?
  • Which essential measurements or observations are likely to answer those questions?
  • How are the detectors constructed in order to optimise the sensitivity?

    Have fun looking into this! There will be an opportunity to ask questions at the beginning of the next lecture. Good luck!....

    Heavy Ion Colliding Beam Experiments

    High energy heavy ion collisions are the best way to pack as much energy into as small a space as possible! The main aim is to identify and study a new phase of matter, known as the `Quark Gluon Plasma', in which hadrons `disolve' and quarks and gluons become unbound. Matter is believed to have existed in this form a split second after the big bang.

    Following on from a long series of experiments at the CERN SPS, the modern state of the art, The Relativistic Heavy Ion Collider (RHIC), is currently running at Brookhaven, Long Island, New York. The Birmingham nuclear physics group are engaged in the STAR experiment where, for example, gold nuclei are collided. PHENIX is the other large-scale RHIC experiment with similar aims. The future lies at the LHC, where the Birmingham particle physics group are involved in the ALICE project, which (along with ATLAS and CMS) will study collisions between lead ions.

    The RHIC Facility at Brookhaven
    STAR experiment
    PHENIX experiment
    ALICE experiment

    Neutrino Oscillation Experiments

    For many years after their discovery, it was assumed that neutrinos were massless. After a few hints to the contrary involving for example the neutrino flux from the sun, the first compelling evidence for neutrino mass was obtained by the Super Kamiokande experiment in Japan in 1998. This came in the form of `neutrino mixing', where a neutrino of one type (e.g. a muon neutrino) turns into (or `oscillates') to another type (e.g. an electron neutrino), a very similar phenomenon to the B meson mixing studied at BaBar and Belle. Such mixing is only possible if the neutrinos have (different) masses. This existence of neutrino mass is the only current solid evidence for physics beyond the standard model!

    A number of subsequent and future experiments have attempted to understand what the neutrino masses actually are and how they come about. This often involves sending neutrino beams over huge distances in order to give them chance to mix before they are detected (Long baseline experiments such as K2K, Minos and Opera). Others are based at nuclear reactors (e.g. KamLAND), or, like Super-Kamiokande, observe neutrinos from the sun or deeper in space.

    Super-Kamiokande Home page or American home page, of user-friendly Irvine page
    K2K experiment
    Minos experiment
    OPERA experiment

    Updated 6 October 2008, PRN