What Happens When Things Go Near the Speed of Light?

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Fermilab Experiment E687

In this experiment, a high-energy photon strikes a stationary chunk of beryllium. This collision occasionally results in the creation of a charmed meson (D0). Charmed mesons do not live very long before they decay into two other particles, a pion (π) and a kaon (K). The D0 has a lifetime of 4.0 x 10-13 s. They don't live long enough to travel very far through the detector--unless they are going very fast! This activity will help you to explore that very thing.

You should see an animation on the right. If you don't, you need to get the Shockwave Plug-In and reload this page.

Get on with it!

<IMG src="graphics/decay_anim.gif" width=100% height=100%>
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