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Homework Help: Particle physics lab: techniques

  1. Nov 16, 2008 #1
    Hi all,

    I'm measuring multiple coulomb scattering by using 4 chambers filled with He gas, and lead plates between the top 2 chambers and bottom two. The chambers have a potential difference across the plates so when the muons ionize the He gas, a spark is produced. A camera marks the pixels of the sparks.

    1. The problem statement, all variables and given/known data

    The computer program written in root plots number of events (y) vs scattering angle (x). The fit to the data points is a double gaussian.

    [itex]
    f(x)= e^{- \frac {x^2} {2 \sigma_1^2}} + e^{- \frac{x^2} {2 \sigma_1^2}}
    [/itex]

    We'd like to see, for more lead plates a larger scattering angle distribution (i.e. Sigma to increase). The problem is, the experiment with zero lead plates produced non-zero scattering angles (expected), so I'd like to subtract the straight through data (zero lead plates) from the data that has a non-zero number of lead plates. This is what I'm not sure how to do.

    2. Relevant equations



    3. The attempt at a solution

    From my limited understanding of probability: if X is a continuous random variable that is normally (gaussian) distributed with parameters mu and sigma^2, then
    [itex]
    Y= \alpha X+ \beta
    [/itex]
    with parameters
    [itex]
    \alpha \mu + \beta
    [/itex]
    and
    [itex]
    \alpha^2 \sigma^2
    [/itex]
    So can I somehow linearly convert the non-zero lead plate distributions to one that has the zero-plate scatter distribution subtracted?
     
  2. jcsd
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