Standalone toy MC simulation for a high precision timing detector in CMS

1. Standalone toy MC simulation for a high precision timing detector in CMS Sepehr Ghazi Nezami Adi Bornheim, Artur Apresyan

2. Luminous region vs crossing angle

4. Rechit energy spectrum EB, MinBias Pile up rechit distribution from minimum bias trigger : Plot below : ~14000 collision events with ~20 PU events each  300000 individual PU interactions We see eg. 1000 rechits at 10 GeV and 10000 rechits at 1 GeV. Expect 7000@10 GeV, 70000@ 1 GeV for 140 PU events #rechits Log(Erechit)

5. MinBias rechit eta distribution EB 2nd order polynomial describes the eta distribution well in EB 80000 rechits with a threshold of 1 GeV, 8000 events 10 rechits in barrel per event above 1 GeV at 20 PU  ~70 rechits above 1 GeV at 140 PU

6. Rechit energy spectrum EE, MinBias EE data has cut on ntuple level, Artur is fixing this Slope the same, rate higher

7. EB EE E>1 GeV 78500 E>2 GeV 12894 E>3 GeV 4829 E>4 GeV 2628 90781 E>5 GeV 1732 50671 E>6 GeV 1217 30464 E>7 GeV 885 19544

8. #rechit(E>4GeV) vs eta

10. Spike cut effect of PU rechit distribution • PU rechit distribution is from 2012 ECAL NSZ data

11. Timing vertex with rechit distribution using spike cuts • Smoother transition EB to EE • Some additional differences vs eta to be understood Group Meeting With spikes Without spikes

13. First attempt on low pT forward jets Dataset : MultiJet1Parked_Run2012B-05Nov2012-v1 /eos/cms/store/group/phys_susy/razor/apresyan/ProdSummer12/JME/MultiJet1Parked_Run2012B-05Nov2012-v1_NoVtxFilterNoEECut_block1 /eos/cms/store/group/phys_susy/razor/apresyan/ProdSummer12/JME/MultiJet1Parked_Run2012B-05Nov2012-v1_NoVtxFilterNoEECut_block2Why is the jet pT limited to >50 GeV ?

14. First attempt on low pT forward jets Dataset : MultiJet1Parked_Run2012B-05Nov2012-v1 /eos/cms/store/group/phys_susy/razor/apresyan/ProdSummer12/JME/MultiJet1Parked_Run2012B-05Nov2012-v1_NoVtxFilterNoEECut_block1 /eos/cms/store/group/phys_susy/razor/apresyan/ProdSummer12/JME/MultiJet1Parked_Run2012B-05Nov2012-v1_NoVtxFilterNoEECut_block2Why is the jet pT limited to >50 GeV ?

16. I have 115451 events -> each has 13 vertices. I just have counted rechits with energy>4GeV (below 4 GeV is not important, Since I have a cut on rechit energy = 4GeV in the timing algorithm) Number of all rechits: 2872026 Number of all rechits not in Jet 1 and Jet 2 (candidates for PU): 1387512 PU per Vertex = 1300000/(13*110000) = 1 -> so it seems 1 PU per Vertex might be a good approximation for whole the ECAL. I used it because I could not find number of PU rechits for whole ECAL in your plots. I could correct is easily since it is just change of a number. Also I think in the plots you send x axis is log in base of e instead of 10. Am I right? I am still a little confused :) I attached PU rechit Energy Distribution. It is similar to your plot and since I have the histogram in root file it is easier to use. I can use it until I completely understand your plots but for now I thought it would be a fast solution. whit these configurations we have these results: for 0.1 ns resolution and 140 PU -> 140.png for 0.1 ns resolution and 20 PU ->   20.png for 0.1 ns resolution and 0 PU ->     0.png

17. 100 ps resolution PU20 PU140 PU0

18. 1. I have 5000 events each one 20 PU -> 100000 PU Interactions. 2. I use your plot for energy distribution. I found out that I need 20 rechits per PU vertex above 1 GeV to have .5 rechit per PU vertex above 4GeV (from you energy distribution plot). So I set each PU Vertex to have 20 rechits above 1 GeV. From Eta distribution we see the fraction of rechits in the barrel is very small (about 0.005). when I want to count number of rechits above 1GeV in the barrel I get 8500 -> 1.6 per event while it should be 10 from your slides (Slide No. 5). It might be cause by an error in my attempt to fit lines to your plots by eye, in that case I would change the distribution. I attached eta and energy distribution of PU rechits.