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Centrality Dependence of φ production. Data sample. Production 01J (2000 low-intensity min. bias Pb+Pb @ 158A GeV 26 runs (4016 – 4102); 335,159 events on DST use calibrated E veto for event selection. Problems. see NA49/NA61 collaboration meeting, 7 June 2011.
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Data sample Production 01J (2000 low-intensity min. bias Pb+Pb @ 158A GeV 26 runs (4016 – 4102); 335,159 events on DST use calibrated Eveto for event selection
Problems see NA49/NA61 collaboration meeting, 7 June 2011 Disagreement of results for C1 (5% most central) with published results Disagreement of results for peripheral events (C4, C5, C6) with preliminary results shown in QM 2001 Event numbers after cuts disagree with those used in other analyses (statement of H. Stroebele
Event Cuts to remove non-target interactions and badly reconstructed events • Success of vertex fit: vertex.iflag = 0 • z position of reconstructed vertex • Others: (do not play a role here) • S3 • total number of tracks • number of tracks with dE/dx
Cut on vertex-z position all events Cut on vertex.iflag removes 0.4% of events (mostly for positive vz) Double-peak structure in vz (0 cm, 1 cm) cut: abs(vz) < 1 cm, removes 41.3% of events
Cut on vertex-z position C1 No non-target interactions here (?) Cut on vertex.iflag removes 0.4% of events (mostly for positive vz) Double-peak structure in vz (0 cm, 1 cm) cut: abs(vz) < 1 cm, removes 8.7% of events should second peak be used?
Eveto Distribution are these the „canonical“ values?