MDC Simulation & Digitization

1. MDC Simulation & Digitization Yuan Ye 20050921 BesIII Software Meeting

2. Cell Equal Division Wire Layer Construction Sensitive Area Sensitive Area • Straight Wire • Ideal Position

3. Hit Record every hit LayerNo CellNo Edeposit Ddift Ttof (Global time from event begin) global  local

4. Digitization • Loop over all hits, combine hits from same cell to one Digi • Edigi=Edeposit • Ddigi • Energy cut Now Emin=0, needed • T Do X-T conversion, T =Ttof + Tdrift • Ddrift of minimum T

5. Digitization(Cont.) • Smear • Get Spatial Resolution from Cal. x=(f 12+(1-f) 22)1/2 • Sample between 12 use f Possible correction: Edigi • Electronic correction 20m: 2= 1,22- electronic2 • Sample use  Ddigi=Ddigi+ Dsmear If Ddigi<0, do again

6. Digitization(Cont.) • X-T conversion Ddigi Tdrift • Create Tdigi • Tdigi = Tdrift + Ttof + Ttransfer • Possible Correct : Edigi & threshold • T to TDC

7. Multiple Scatter vs Step Limit @1GeV StepLimit 5 4 3 2 1.5 1 cm pt 11.1 7.8 4.9 4.1 4.0 3.5 Mev Now we set default is 2cm

8. Background • Two methods: • Add in digitization use some model (done) • Digi mix (future) Mix background from data with MC

9. Thanks!