1. FRANCESCO NOFERINI (INFN CNAF – INFN BOLOGNA) 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances GRID and  analysis in pp 1

2. ɸ analysis – the procedure Efficiency estimate  Particle Identification (PID) efficiency for kaons  From kaons efficiency to ɸ efficiency Corrections  Mass resolution from the tracking  Shift on the mass from the tracking Systematics effects  For tracking  For PID p T spectrum ɸ properties : (mass, width) 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 2

3. p T spectrum corrected for efficiency 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances (II) 3 5.6M ppMB at 10 TeV 78M ppMB at 10 TeV Systematics evaluated with MC TOF time resolution  T0 resolution = 80 ps

4. Mass resolution from the tracking 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 4 all p T

5. ɸ properties : (mass, width) 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 5 74M ppMB events Effect due to the acceptance (0.1%) Integrated on the whole p T range from Monte Carlo “truth”

6. ɸ properties : (mass, width) (Voigtian = Breit-Wigner  gaussian) 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 6 realistic analysis Background fit 78M ppMB events

7. ɸ properties : (mass, width) (Voigtian = Breit-Wigner  gaussian) 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 7 realistic analysis Background fit 5.6M ppMB events

8. p T spectrum for TOF time resolution of 130 ps 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 8 Reconstructed spectrum corrected for efficiecy. The current statistics is enough to perform such measurements in the first days of data acquistion. A sample of 1.8M ppMB ( √s = 10 TeV) events was generated with PYTHIA6 and used to perform the following analyses. The first analyses on real data (pp@900GeV) are confirming the hypoteses assumed in these studies (T0 resolution, TOF time resolution, …) Presented at IFAE ‘09(Bari, 16th April) TOF time resolution = 130 ps LHC clock T0 resolution = 160 ps TOF T0 resolution  50-60 ps

9. PbPb MB results (preliminary) 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 9 90% of background (same sign kaons) subtructed No background subtruction

10. Preparation of publication of an early physics paper 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 10 Title Production of ɸ mesons in pp collision at √s = YY TeV Abstract We present the study of ɸ resonances in the first pp(YY TeV) Minimum Bias collisions at the LHC with the ALICE detector. With a statistics of XX M of events we perform the reconstruction of the meson using the particle identification of the time of flight detector (TOF) in the kaon channel. Structure physical motivation for this study central apparatus description + trigger (definition of MB) tracking + identification techniques (TOF) all efficiency corrections (including systematics) results: spectra vs pt + mean&width for the resonance + ratio w.r.t. kaons comparison with MC (Pythia, …) Tables selection parameters yields vs. p T fit parameters (vs. p T ) Figures invariant mass distribution p T distribution ratio ɸ /K (vs. p T )

11. First look at ppMB data - √s = 900 GeV 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 11  K p 1° day results PRELIMINARY results on 7/12/2009 collisions on 6/12/2009 T0 from TOF when available (if not from the machine clock,  beam-beam < 160 ps) Run: 104068, 104070, 104157, 104159 N events SPD = 4222 N T0-TOF =262

12. TOF resolution and abundancies 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 12 N events = 26726 N events SPD = 7367 N events T0-TOF = 478 N tracks TOF = 2123 PRELIMINARY With time slewing correction

13. TOF resolution and abundancies 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 13 N events = 26726 N events SPD = 7367 N events TOF-T0 = 478 N tracks TOF = 2123 PRELIMINARY

14. Event time (T 0 -TOF) efficiency 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 14 N events

15. T 0 -TOF 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 15 Run 1 Run 2 N events

16. Backup 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 16

17. PID Efficiency (Contamination) 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 17 TOF resolution at 80 ps (final resolution) TOF resolution at 130 ps (current resolution) Efficiency contamination

18. Calcolo parametri della ɸ con risoluzione realistica (Voigtian = Breit-Wigner  gaussiana) 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 18 con l’effetto dovuto al Background subtraction 74M ppMB events Sovrastima dovuta a fondo residuo (2-3%)

19. 08/12/2009 ALICE TOF - general meeting - F. Noferini - GRID and resonances 19

20. 03/12/2009 - giovedì Meeting TOF offline - F. Noferini - task performance 20 ppMB 193k eventi PYTHIA

21. 03/12/2009 - giovedì Meeting TOF offline - F. Noferini - task performance 21 ppMB 193k eventi PYTHIA