Spectrum Visualiser is a Java applet which downloads a meson data file and displays it. States are plotted as clickable boxes. Box colours are assigned as follows:

• experimental states
• recent experimental states
• molecular candidates
• hybrid candidates
• glueball candidates
• theory predictions

Start by choosing a particle type under the button "expt".

• expt select PDG particles
• qm/thy select theoretical quark model mass predictions (from Godfrey and Isgur, 1985).
• recent select recent additions to the data base.
• hybrids select experimental hybrid candidates
• hybrids/theory select lattice hybrid predictions
• glueballs select experimental glueball candidates
• glueballs/theory select lattice glueball predictions
• molecules select meson-meson bound state candidates

Under "lines" you can also choose the size of the box to reflect mass errors, particle widths, or nothing at all (the default, "lines").

Then choose a flavour under "uu". (NB: uu (ud) denotes isoscalar (isovector) light mesons).

Then press "plot". You should see a diagram of your selected mesons sorted by J^PC and plotted vs. mass. If you select new mesons, you'll need to click "plot" again.

Clicking on "+" or "-" will raise or lower the bounds of the plot.

Selecting "grid" will draw grid lines with your plot.

If "pop up" is selected information about a state will appear as the mouse is moved over a box. Clicking on the box will display further information on the state.

Comparing data.

You can compare experimental data to theoretical predictions. This is done by

1. selecting the experimental data
2. press "plot"
3. click "compare"
4. select the theoretical predictions
5. click "plot"

Known Bugs

Netscape 4.5b1 will sometimes freeze the "expt/errors" and "uu" buttons when you resize the screen. You can thaw them by clicking "back" on the browser and then returning to the Visualiser page.

Scrollbars may not appear when necessary. They can be made to appear by resizing the window slightly (perhaps twice).

Netscape 4.06 appears to work!

Mysterious Java security exceptions seem to occur randomly. The only solution seems to be logging off and on again (!?)