1. e + /e - ID with Prs Grigory Rybkn, INR/Troitsk Ivan Belyaev CERN & ITEP/Moscow

2. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 2 Introduction Preshower Important (and vital) for L0 Trigger Important (and vital) for L0 Trigger Fast and “efficient” e/h separation 10 m.i.p cut e/h enrichment of about 10 (TDR note) Could (and should) be used for off-line e + /e - ID Could (and should) be used for off-line e + /e - ID Should provide brilliant separation for clean environment Very simple analysis Get the track Get the track Get connected “charged” cluster in Ecal Get connected “charged” cluster in Ecal  2 < 49  2 < 49 at least 1 “hit” in Spd at least 1 “hit” in Spd at least 1 “hit” in Prs at least 1 “hit” in Prs Select “useful” Prs hits Select “useful” Prs hits Tolerances? Tolerances? Study the energy deposition in Prs Study the energy deposition in Prs

3. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 3 Prs deposition for e + /e - 1 mip = 2.7 MeV

4. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 4 Prs deposition for hadrons 1 mip = 2.7 MeV

5. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 5 Prs deposition for ghosts 1 mip = 2.7 MeV “Ghosts” have sizeable e + /e - -like component

6. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 6 Prs deposition

7. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 7 Efficiency for 12 MeV cut Almost “flat” efficiency for e + /e - Quite pure rejection of non e + /e -

8. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 8 Efficiency for 19 MeV cut

9. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 9 Efficiency for 25 MeV cut

10. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 10 Efficiency for 30 MeV cut

11. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 11 Efficiency for 35 MeV cut “Non-flat” efficiency for e + /e - Reasonable rejection of non e + /e -

12. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 12 Efficiency for 25 MeV cut ???

13. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 13 Efficiency for 25 MeV cut sweeping/nonsweeping region

14. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 14 Efficiency for 25 MeV cut no shower tolerance

15. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 15 Efficiency for 25 MeV cut 3mm shower tolerance

16. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 16 Summary I

17. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 17 Summary II

18. 5 Nov'2k+2 Calorimeter Ivan Belyaev LHCb CERN & ITEP/Moscow 18 Summary III e/h separation with Prs was studied e/h separation with Prs was studied With 20 MeV cut for preshower energy one could get reasonable efficiency for electrons and rejection of true hadrons of 10 and better With 20 MeV cut for preshower energy one could get reasonable efficiency for electrons and rejection of true hadrons of 10 and better Rejection of ghosts is not perfect Rejection of ghosts is not perfect Again the evidence of sizable e + /e - -like component for ghosts Again the evidence of sizable e + /e - -like component for ghosts P t -dependency has “strange” shape P t -dependency has “strange” shape To be done Understand the results Understand the results Find reasonable momentum dependent threshold Find reasonable momentum dependent threshold C++ code to Brunel/DaVinci C++ code to Brunel/DaVinci