D Had Analysis - Process - m BC pi 0

Introduction

If we look at the deltaE (deltaE = E_reco - E_beam) distribution of the mode 1 where D decays to K pi pi0 for Data and MC. We can see that the peak of signal MC is shifted to higher side compared with data. From the plot, Mean_signal = -0.0043, Mean_data = -0.0056.

Data

Signal MC

Process

To compensate this shift, we can rescaple the pi0's momentum in

signal MC by a factor of 0.997. Then the deltaE plot for signal MC will be consistent with data as shown below. Where the mean value of deltaE changed from -0.0043 to -0.0056, consistent with data.

After rescaling the pi0's momentum, we can see the mbc also

changed - less than 0.03% level as shown in the plots below.

Conclusion

Then we fit the momentum rescaled events and compare the result² with the regular one. The difference is negligible.

Name	mbc/calc/pi0/0.997	regular	diff(%)
N1	69769 ± 284	69799 ± 284	-0.04 ± 0.58
N2	70859 ± 286	70891 ± 286	-0.04 ± 0.57
Nbkgd1	9004 ± 142	8975 ± 141	0.33 ± 2.23
Nbkgd2	8903 ± 141	8877 ± 140	0.30 ± 2.23
md	1.86470 ± 0.00001	1.86466 ± 0.00001	0.00186 ± 0.00043
p	0.89 ± 0.03	0.87 ± 0.03	2.05 ± 5.45
sigmap1	0.00703 ± 0.00004	0.00694 ± 0.00004	1.39 ± 0.83
xi	-44.75 ± 1.72	-43.57 ± 1.71	2.72 ± 5.57
chisq1	139	126	10.39
chisq2	94	76	23.31

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1. For plots about the other charge conjugate etc see here.

2. For details of the fitting see here.