Mad Andrew's Journal

A little Friday afternoon physics
You may want to skip this one, but I feel like posting it anyway.

When you collide protons and anti-protons you create a lot of stuff. Some of it decays into muons.
Bear with me. I look for W->munu so that I can normalize my background estimate for WGamma->munugamma.
Clear so far? Here's where it gets tricky: Some 'stuff (kaons, pions. mmmm. pions...)' decays IN-FLIGHT into muons. Which means while my central detector is trying to make a track for the first particle, it decays (making a kink in the track), and spits out a lower energy muon than the parent particle. This 'kink' doesn't have to be that big to screw up the measurement of the momentum. So presto, artificial W looking thing. However, we are not without hope. There is another detector (the muon system) which definitely tells what the muon momentum is. Though badly. Very badly. It looks like that by requiring the central track to be high momentum AND the muon spectrometer track to be vaguely straight, the decay in flight problem may be solved.

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