Systematic Uncertainties
•dN/dh
¨Background subtraction on tracklets < ±5%
¨Uncertainty on a due to model differences < 5%
•Total contribution due to feed-down correction < 4% (typically 1%)
•Total fraction lost due to stopping particles < 5%
•Both are corrected via MC normalization
¨Total uncertainty on dN/dh is ±8%
•áNpartñ
¨Loss of trigger efficiency at low-multiplicity <10%
•Uncertainty on áNpart ñ <1%
¨Uncertainty in modeling paddle fluctuations
•Uncertainty on áNpart ñ <6%
•( dN/dh / áNpartñ )130 / ( dN/dh / áNpartñ )56
¨Many uncertainties cancel in the ratio
¨