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Mass of Z Activity

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A short intro to CERN...

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Intro to CMS (watch ~2 mins from 1:42-3:50)...

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One possibility: A neutral particle (Z boson, for example) is produced - decays to 2 muons

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The more general version of E=mc2...

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For each event - mass (of decayed particle) is calculated...

  • c is a constant...the speed of light
  • p is the total (vector sum) of the momentum from the two muons
  • E is the total energy of the two muons

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About the units… “back of the envelope”-style

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How do we find total energy (E) of the two muons?

  • Scalar addition - yeah, it’s that easy. �But wait...aren’t these momentum measurements???

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Finding the energy

of each muon…A side note for those who �are interested...

When we take the square root of both sides, we get right back to the same number with slightly different units: 49.7 GeV. (This works well for particles of very small mass.)

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How do we find total momentum (p) of the two muons?

  • Vector addition!
    • Add the vectors to to get the total momentum

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Back to this...For each event - mass (of decayed particle) is calculated...

  • c is a constant...the speed of light
  • p is the total (vector sum) of the momentum from the two muons
  • E is the total energy of the two muons