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2006 EEMC Neutral Pions: New Mass Fitting

Updated on Sun, 2013-03-03 17:07. Originally created by drach09 on 2013-03-03 17:06.

I have, now, applied the new background fitting method which extends the range to 0 < mγγ < 0.3 GeV/c2. The systematics have also been recalculated.

Figure 1

The new results look qualitatively similar to the previous measurements. I have dropped the lowest pT bin as we have much trouble getting the simulation to agree with data. Likely, this is due to the fact that few pions below 4 GeV/c can fire the trigger.

Figure 2

New Fitting Old Fitting (Expanded Run List)

In Fig. 2 I compare the new results vs. xF with the old. Note: I have changed the vertical scale.

Figure 3

New Fitting Old Fitting (Expanded Run List)

In Fig. 3 I compare the new results vs. pT with the old. Again, I have changed the vertical scale and dropped the lowest bin.

Table 1: New Fitting

  pT Blue pT Yellow xF Blue xF Yellow
χ2/ν 5.31835/7 10.8541/7 0.747144/2 3.26338/2
p0 0.00330197± 0.0105832 0.0029089±0.0102665 0.00349719±0.0106989 -0.00151564±0.0103378

Here I have fit the p0 distirbutions with a constant. The fits are nicely consistent with 0 with χ2/ν not entirely ridiculous.

Table 2: Old Fitting (Expanded Run List)

  pT Blue pT Yellow xF Blue xF Yellow
χ2/ν 5.35085/8 14.0435/8 0.607805/2 3.6786/2
p0 -0.00272623±0.00973172 0.00339444±0.00942069 -0.00346015±0.00958788 0.00498536±0.00926762

Here I show the fits for the old mass-fitting technique for comparison.

Table 3: Expanded Run List (xF > 0)

  AN δAN Stat δAN Total Syst δAN B.g. Asym Syst δAN Sig. Fit Param. Syst δAN Sig. Frac. Syst δAN Mass Window Syst δAN Non-coll. Bg. Syst
xF Bin 1 0.0189 0.0222 0.0155 0.0056 0.0023 0.0091 0.0108 0.0020
xF Bin 2 0.0158 0.0215 0.0126 0.0059 0.0023 0.0073 0.0078 0.0020
xF Bin 3 -0.0258 0.0620 0.0215 0.0163 0.0077 0.0040 0.0108 0.0020
pT Bin 2 0.0796 0.0432 0.0487 0.0012 0.0078 0.0478 0.0043 0.0020
pT Bin 3 0.0109 0.0264 0.0072 0.0037 0.0016 0.0051 0.0022 0.0020
pT Bin 4 0.0039 0.0280 0.0082 0.0062 0.0011 0.0028 0.0041 0.0020
pT Bin 5 0.0487 0.0377 0.0238 0.0087 0.0076 0.0122 0.0166 0.0020
pT Bin 6 -0.0142 0.0545 0.0113 0.0099 0.0015 0.0014 0.0047 0.0020
pT Bin 7 -0.0525 0.0857 0.0339 0.0109 0.0185 0.0024 0.0260 0.0020
pT Bin 8 -0.0918 0.0968 0.0812 0.0113 0.0306 0.0141 0.0730 0.0020
pT Bin 9 -0.2615 0.1708 0.1846 0.0075 0.1121 0.0988 0.1081 0.0020

Table 4: Expanded Run List (xF < 0)

  AN δAN Stat δAN Total Syst δAN B.g. Asym Syst δAN Sig. Fit Param. Syst δAN Sig. Frac. Syst δAN Mass Window Syst δAN Non-coll. Bg. Syst
xF Bin 1 0.0017 0.0214 0.0072 0.0036 0.0001 0.0006 0.0059 0.0020
xF Bin 2 -0.0101 0.0207 0.0170 0.0040 0.0010 0.0033 0.0160 0.0020
xF Bin 3 0.0016 0.0606 0.0402 0.0106 0.0007 0.0012 0.0388 0.0020
pT Bin 2 0.0385 0.0419 0.0235 0.0008 0.0035 0.0216 0.0084 0.0020
pT Bin 3 -0.0057 0.0256 0.0222 0.0027 0.0005 0.0013 0.0219 0.0020
pT Bin 4 -0.0003 0.0273 0.0103 0.0041 0.0000 0.0003 0.0092 0.0020
pT Bin 5 0.0364 0.0361 0.0124 0.0052 0.0050 0.0094 0.0030 0.0020
pT Bin 6 -0.0042 0.0535 0.0273 0.0058 0.0009 0.0012 0.0265 0.0020
pT Bin 7 -0.1261 0.0870 0.1003 0.0063 0.0513 0.0069 0.0856 0.0020
pT Bin 8 0.0001 0.0956 0.0412 0.0096 0.0000 0.0007 0.0400 0.0020
pT Bin 9 -0.0488 0.1553 0.0838 0.0062 0.0215 0.0123 0.0798 0.0020

In tables 3 and 4 I print the data for the various plots. Note, I have included the non-collision systematic for good measure. Additionally, I have included the alternate mass fitting method which we may not need with the improved Monte Carlo template fitting.

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