Kinematics: Beam energy = 5.650 GeV,
Target: 4 cm LH2 for electron runs, 15 cm LH2 for positron runs
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1.5 | 0.9 | 0.55 |
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0.000 | 0.000 | 0.000 |
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2.981 | 204.446 | 1607.051 |
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4.793 | 250.74 | 1579.9 |
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0.4993 | 1.684 | 3.8437 |
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0.305 | 1.324 | 2.219 |
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0.0110 | 0.2514 | 1.5205 |
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0.2016 | 1.3317 | 5.2569 |
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0.00465 | 0.00568 | 0.00859 |
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0.01092 | 1.00106 | 11.19969 |
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0.00072 | 0.20570 | 2.49902 |
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0.000 | 0.000 | 0.00000 |
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5.843 | 105.640 | 299.588 |
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0.000 | 0.000 | 0.000 |
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9.445 | 129.764 | 429.775 |
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23.775 | 188.286 | 300.538 |
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0.00424 | 0.00194 | 0.00138 |
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0.02140 | 0.51726 | 2.08786 |
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0.00686 | 0.00239 | 0.00198 |
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0.03459 | 0.63539 | 2.99515 |
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0.036 | 0.155 | 0.4754 |
The internal radiation length used in Wiser's fit is: 2.7%
The radiation length used in rosetail is:
for 4cm liquid H target
before interaction: 2.8 mil Al + 4 cm/2 LH2 = 0.08% + 0.23%= 0.31%
after interaction: 4 cm/2 LH2 + 7 mil Al/ + 16mil Al + 20 cm Air + 7 mil Kapton
= 0.23% + 1.01% = 1.24%
From the table above we compare data with wiser OR epc code for pion, and compare data with (whitlow+rosetail) OR (qfs+rosetail) for . From the comparison we can see that wiser gives good result for
cross section, and whitlow's fit is good for
cross section. However, there is an overestimation in wiser's code for
cross section. We expect this is because we didn't include the angular distribution of
. We will include this in the future. At present we just take this overestimation into account when estimating positron background for e99117 runplan.