Weekly report Huiling Li

Weekly report
Huiling Li
1

pC inelastic cross section at
400GeV
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The number of MC events is half that of Data events now.
Incoming particles:
– Identity is proton
– Energy is around 400GeV. Here is 380GeV~400GeV
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Outgoing particles: use BDT to separate survival and
interacting events. For BDT:
– Signal: momentum of TrMCCluster at L9 > 380GeV
– Background :momentum of TrMCCluster at L9

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Preselection:
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BDT variables:
– NParticle=1
– log10(1+TofQL3) shifted
– NTrTrack=1
– log10(1+TofQL4) shifted
– NTrdTrack=1
– log10(PEInRing) tuned
– No TofUpOnTimeClu
– log10(PEOutRing) tuned
– abs(rigiInnL1/400-1)

94.4%
After preselection,
99.8% events have a
proton TrMCClu with
max momentum at
L7/L8.
380GeV
4

For BDT signal and background,
95.1% events have a proton
TrMCClu with a max momentum at
L9.
98.1%
background
Signal:93.3%
380GeV
5

NaF BDT
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Cross section:
– 259.8
– Take noTrkCluOnL9
events as survival
6

Agel BDT
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Cross section:
– 269.8
– Take noTrkCluOnL9
events as survival
For events with NoTrkMCCluL9:
MC: 0.6%
Data: 3%
How to deal with this discrepancy
7

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There are still discrepancies between MC and
data in TFractionFitter:
– I'm using B700 BT.Data. Maybe I need to use
B610 BT.Data, since I'm using B620 BT.MC.
– Is there a standard for TFractionFitter to check
how good the fit is?
– If there is still discrepancy between MC and Data:
reweight MC tofQL3 and tofQL4
8

Probable systematic errors:
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BDT
– Signal and background definition
– No TrMCCluster events at L9
●
Cross section calculation:
– The correctness of BT data position selection
– Geant4 input variables
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MC vs Data:
– Trigger efficiency
– efficiency discrepancy between MC and data
9