BigBite Optics #4
Matrix elements "[TgPh|FpPh]" and "[TgTh|x]"
I am still trying to determine matrix elements for target variables TgPh and TgTh.
I believe there are two ways to to that. In first approach we can use elastic runs. Since
we know the direction of q-vector we can precisely determine both matrix elements from
comparison of the focal plane angles with the q-vector angles (rotated to correct coordinate
system.) The second approach is to use quasielastic data with BB-sieve in. Quasielastic data
cover the whole acceptance of the BB, which is very good, however, for the quasielastic data we can
not determine target angles directly from q-vector. Therefore we need sieve-slit. In order to use it, we
also need to know the precisely distance from the target to the sieve. This distance was never measured
directly in our experiment. Here are my notes on how I tried to determine it.
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Here is Mathematica file, that I was using with my calculations: BB_Measurements.pdf
Here are my current results for the sieve slit. We can see that there is still a lot of work that
needs to be done... especially on the accuracy on the edges of the acceptance and with the TgTh variable.
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Last modified: 03/10/10
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