Corrections,systematic errors
a(zvtx)
•Calculated from MC studies
•90% contribution
from known g
•geometrical
acceptance
generator: HIJING
1.35
simulations: Geant
3.21
Sources
of systematic errors
•Background subtraction
•Uncertainty on a due to model differences
•feed-down from strange decays
•stopping particles
Total
uncertainty on dN/dh is ±8%
good understanding of detector geometry
and tracking efficiency
spec
vtx
130
GeV
56 GeV