I do research on particle physics, which is the science of the smallest of matter. Below two descriptions can be found - the first one very introductory (no knowledge of physics required), while the second one is more technical (knowledge of physics somewhat required).

Current Research (introductory description)

Atoms are made of electrons circling around a nucleus consisting of protons and neutrons, which again are made of quarks. It is the understanding of the proporties and interactions of quarks and electrons (and related particles - see chart) that is the goal of particle physics, which is intimately linked to the birth and current state of the Universe we live in today. While the length scale of atoms is about 1/, the sizes relevant in particle physics is 1/ or ten billionth the size of atoms (i.e. if atoms had the size of the Earth, particle physics would take place at the submillimeter scale). The study of such tiny objects is done with (large) accelerators and particle detectors. Physicists accelerate particles to extreme energies, collide them, and then study the debris flying through the detector. Why? Well, an analogy is a world, where one suspects that everything is made of small mechanical devices (for example a classic alarm clock) instead of atoms. Objects much to small to study in a microscope. A way to test the suspicion and further investigate the building blocks of clocks would be to collide the clocks and study what comes out of these collissions. At a certain force, one of the bells might come off, and one would then see a bell in the detector. At greater force more inner workings such as springs and wheels will be seen, and by repeating the process many times, one will slowly get a picture of what a clock consists of.
This is exactly what particle physicists do!
By repeatedly colliding particles at increasing energies and studying the outcome, the Laws of Nature governing the building blocks of the Universe have been mapped out. However, since we live in a Univers of relativity and quantum mechanics, things are slightly more complicated. First of all, in addition to looking into the constituences of matter, new particles can be produced and thus discovered.
An example of such particles are the W and Z bosons, which are the particles responsible for the Weak force, in the same way as the photon "carries" the ElectroMagnetic force. However, contrary to the photon the W (and Z) is massive, which is the very reason for the Weak force to be weak. The W and Z boson and their masses were predicted by Glashow, Weinberg, and Salam (Nobel Prize 1979), and discovered at CERNs SPS accelerator (invented by Rubbia and van der Mer) a few years later (Nobel Prize 1983).
Interestingly, the mass of the W plays a new role in predicting the mass of an even heavier particle, namely the Higgs particle, which is responsible for the mass of all other particles. However, the prediction of the Higgs mass requires very precise input values of the W boson and top quark mass.
At the ATLAS experiment I work on a precise measurement of the W boson mass.

Current Research (technical description)

The mass of the W has already been measured to be MW = 80.425 ± 0.034 MeV (PDG 2004), but a more precise result is desired for two reasons: In addition, the W and Z bosons will be used for all kinds of calibration, alignment, and cross checks, and will therefore play a central role in the first period of the LHC era.
The W mass can be measured in many ways, as both the methods and the observables are several. The two principle methods are: The two methods are not as different as they may sound, as both rely on the Z decays for calibration. However, the ratio method avoids having to produce large amounts of Monte Carlo, who's preciseness can be brought into question, and thus this will most likely be the method used.
The quantities sensitive to the W mass are generally the following three: Since only the transverse (and not the longitudinal) missing momentum can be measured, the longitudinal momentum (and hence pseudo-rapidity) of the W is unknown. For this reason all three quantities are transverse and therefore boost invariant. Since the transverse mass is partially derived from the two others, the three are correlated, which will have to be taken into account when combining results. However, since they don't have exactly the same systematic errors, some may be diminished in the combined result.
A further subdivision in pseudo-rapidity is also likely, as both the efficiency, the precision, and the systematics vary in this dimension. Given that the first year of low luminosity running of the LHC will yield 300 million W's and 50 million Z's, it is clear that the measurement of the W mass will be limited by systematic errors.
The aim of the analysis is an overall error of less than 20 MeV.

Finally, a remark on how seemingly "useless science" has given so many technologies to our world. Quoting Glashow, here is a list of ten not-so-useless things, which owe there invention to modern "seemingly useless" science:
  1. Computers (technical advancement for building the atomic bomb).
  2. World Wide Web (coordination in experimental particle physics).
  3. Global Positioning System (atomic clocks for testing relativity).
  4. Radioactive isotopes (now essential in medicine and leak searching).
  5. Beam technology in medicine (quantum mechanics and X-rays).
  6. Medical imiging (invented "for fun" in researchers spare time).
  7. Superconductivity (commercially available due to accelerators).
  8. Syncrotron radiation (spin off of accelerators used in material science).
  9. Kryptology (abstract math).
  10. Neutron (power production).
    Updated: 18th of October 2001. Mail me: