General information

Data used

LHC11h(pass2)
AliROOT tag v5-03-35-AN 
AODs from AOD095

 Int_t run_numbers[49]={167915,167920,167921,167987,167988,168069,168076,168105,168108,168115,168173,168181,168311,168318,168322,168325,168341,168342,168361,168362,168460,168464,168467,168511,168512,168514,168777,168826,168988,168992,169035,169091,169094,169411,169415,169417,169550,169588,169835,169837,169838,169846,169855,169858,170040,170081,170228,170268,170387};      

General cuts

Event Cuts:

|vertexZ|<10cm
Centrality<80%

Track Cuts:

   trackCuts->SetClusterRequirementITS(AliESDtrackCuts::kSPD,AliESDtrackCuts::kAny);
   trackCuts->SetRequireTPCRefit(kTRUE);
   trackCuts->SetRequireITSRefit(kTRUE);

  AliDielectronVarCuts *pt = new AliDielectronVarCuts("ptCut","pt cut");
  pt->AddCut(AliDielectronVarManager::kPt,1.,1e30);
  pt->AddCut(AliDielectronVarManager::kKinkIndex0,0.);
  //AOD additions since there are no AliESDtrackCuts -----------------
  pt->AddCut(AliDielectronVarManager::kEta,-0.9,0.9);
  pt->AddCut(AliDielectronVarManager::kImpactParXY, -1.0,   1.0);
  pt->AddCut(AliDielectronVarManager::kImpactParZ,  -3.0,   3.0); 
  pt->AddCut(AliDielectronVarManager::kNclsTPC,95.,160.);

Lint Estimation (Gamma trigger EMC)

• [Lint estimation in PbPb(EMCEGA) - AOD

Event Selection (Gamma trigger EMC)

 A total of 2.2M events passed the physics selection. The number of events that passed centrality cuts + |vertexZ| < 10cm follows:

 N Events(0-80): 1.82 M
 N Events(0-40): 1.3 M
 N Events(40-80):520 k

The centrality distribution is shown below:

Figure (a) - Centrality	Figure (b) - Centrality in log scale

The EMC L1 Gamma trigger is more selective towards more central events < 40%. The distribution above shows that the centrality distribution has it mean value at 29.3%. One could expect, as it will be shown in results, that most of the J/Psi yield will be in this range of centrality.

Figure (c) - Vertex Z

Figure (d) - Multiplicity V0	Figure (e) - Multiplicity V0 in log scale

Figure (f) - Multiplicity V0 x Centrality

Results

1 - Centrality 0-80 %

Ptpair > 5 GeV/c

-1.5 < NSigmaTPC < 3.
pt leg > 1.5GeV/c
1 leg with |NsigmaEMCal< 3. + P > 3 GeV/c + pt > 1 GeV/c

Figure 1(a) - Inv Mass (OS and LS pairs) Centrality 0-80 %	Figure 3(b) -Inv Mass (only OS pairs) Centrality 0-80 %

2 - Centrality 0-40 %

Ptpair > 5 GeV/c

-1.5 < NSigmaTPC < 3.
pt leg > 1.5GeV/c
1 leg with |NsigmaEMCal< 3. + P > 3 GeV/c + pt > 1 GeV/c

Figure 2(a) - Inv Mass (OS and LS pairs) Centrality 0-40 %	Figure 3(b) - Inv Mass (only OS pairs) Centrality 0-40 %

3 - Centrality 40-80 %

Ptpair > 5 GeV/c

-1.5 < NSigmaTPC < 3.
pt leg > 1.3GeV/c
1 leg with |NsigmaEMCal< 3. + P > 3 GeV/c + pt > 1 GeV/c

Figure 3(a) - Inv Mass (OS and LS pairs) Centrality 40-80 %	Figure 3(b) -Inv Mass (only OS pairs) Centrality 40-80 %

-- MarcelFigueredo - 11-Jul-2012