1. The truth information in the hadronic samples

2. Purpose of studying the truth in hadron samples
@2.0 GeV
1+δ was not considered in the scale factor of signal
The background from hadronic is large
Irreducible (on the event topology, quite similar to signal)
Have to look at the truth information to see what kind of background it is

3. Event selection
Good track selection:
Good vertex:
PID
1C fit

4. MC Samples Monte Carlo Hadronic sample from central production
Energy point
Scale factor
2.0
2.05
2.1
2.125
2.15
2.175
1.0874
2.2
2.2324
1.1705
2.3094
2.3864
2.369
Energy point
Scale factor
2.5
2.6444
2.6464
2.7
2.8
2.9
2.95
2.981
3.0
3.02
3.08
What’s the compositions of hadron events passing signal selection?
Scale to data luminosity
Boss p01

5. Truth information selection
Without ISR
2 primary particles
Fill to the 2D histogram if |pdgID| < 500
If |pdgID| >= 500, print out the pdgID
More than 2 primary particles
Print out the pdgID
ISR events:
2 produced particles along with the ISR photon
More than 2 such particles

6. Compositions @2.000 GeV Other:
More than 2 primary particles produced: 35 (7.8%)
More than 2 particles along with ISR photon produced: (2.3%)
Total:

7. Compositions @2.125 GeV Other:
More than 2 primary particles produced: 163 (5.9%)
More than 2 particles along with ISR photon produced: 80 (2.9%)
Total:
Didn’t scale to data luminosity for this energy point

8. Compositions @2.15 GeV Other:
More than 2 primary particles produced: (12.6%)
More than 2 particles along with ISR photon produced: (4.9%)
ISR with primary particles != 1: (0.7%)
Total:

9. Compositions @3.08GeV Other:
More than 2 primary particles produced: (11.0%)
More than 2 particles along with ISR photon produced: (14.2%)
ISR with primary particles != 1: (1.4%)
Primary particles ID > 500: (0.5%)
Total:

10. Summary 1 Black: high statistic; Red: low statistics 2.0 73.9% 11.6%
0.5%
4.2%
7.8%
2.3%
2.05
77.1%
12.3%
0.3%
2.8%
6.3%
1.3%
2.1
64.5%
21.5%
5.5%
6.2%
1.8%
2.125
55.9%
11.3%
1.9%
22.1%
5.9%
2.9%
2.15
74.2%
1.4%
12.6%
4.9%
2.175
76.7%
3.1%
5.6%
11.0%
2.5%
2.2
76.6%
5.3%
12.0%
4.3%
2.2324
82.8%
1.7%
2.2%
7.7%
4.4%
2.3094
84.3% 0%
0.4%
9.6%
2.3864
86.4%
0.8%
7.2%
2.396
84.9%
1.0%
8.1%
3.9%

11. Summary 2 Black: high statistic; Red: low statistics 2.5 89.4% 1.0%
0.7%
4.3%
4.0%
2.6444
87.2%
1.3%
7.0%
3.0%
2.6464
81.8%
2.2%
9.7%
4.8%
2.7
87.3%
2.8%
0.9%
4.6%
3.2%
2.8
90.0%
0.6%
1.8%
4.2%
2.9
70.4%
4.5%
9.4%
13.6%
2.95
77.0% 0%
5.7%
11.4%
2.981
65.5%
8.5%
14.9%
3.0
78.3%
6.5%
13.1%
3.02
55.9%
2.3%
23.3%
18.6%
3.08
66.5%
5.0%
1.4%
11.0%
14.2%

12. Components in figures 1

13. Components in figures 1 (high stats)

14. Components in figures 2

15. Components in figures 2 (high stats)

16. Components in figures 3

17. Components in figures 3 (high stats)

18. Summary After all the event selection
Energy ≤ GeV, most of the events are
Energy > GeV, events are dominated by
The contribution from more bodies decay more and more with energy increasing, but at most 15%
Why ISR events are selected? Will check the photon momentum