The truth information in the hadronic samples

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

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

MC Samples Monte Carlo Hadronic sample from central production Energy point Scale factor 2.0 1.12918 2.05 0.36484 2.1 1.15462 2.125 2.15 0.294743 2.175 1.0874 2.2 1.14026 2.2324 1.1705 2.3094 1.10784 2.3864 0.495147 2.369 0.51375 Energy point Scale factor 2.5 0.0478321 2.6444 0.479812 2.6464 1.07974 2.7 0.0374199 2.8 0.0321977 2.9 1.03345 2.95 0.881449 2.981 0.87135 3.0 0.839721 3.02 0.913752 3.08 1.09535 What’s the compositions of hadron events passing signal selection? Scale to data luminosity Boss 6.6.5.p01

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

Compositions @2.000 GeV Other: More than 2 primary particles produced: 35 (7.8%) More than 2 particles along with ISR photon produced: 10.16 (2.3%) Total: 449.4

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: 2751 Didn’t scale to data luminosity for this energy point

Compositions @2.15 GeV Other: More than 2 primary particles produced: 5.305374 (12.6%) More than 2 particles along with ISR photon produced: 2.063201(4.9%) ISR with primary particles != 1: 0.294743 (0.7%) Total: 42.1

Compositions @3.08GeV Other: More than 2 primary particles produced: 26.2884 (11.0%) More than 2 particles along with ISR photon produced: 33.95585 (14.2%) ISR with primary particles != 1: 3.28605 (1.4%) Primary particles ID > 500: 1.09535 (0.5%) Total: 238.8

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%

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%

Components in figures 1

Components in figures 1 (high stats)

Components in figures 2

Components in figures 2 (high stats)

Components in figures 3

Components in figures 3 (high stats)

Summary After all the event selection Energy ≤ 2.125 GeV, most of the events are Energy > 2.125 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