This page is to support paper http://www.star.bnl.gov/protected/bulkcorr/yili/FlowNonflowWeb/

ΔV{2} fit:

	0-20%	20-30%	30-40%	40-50%	50-80%
v2
v3

Fit function for D = a exp(-Δη/b)+A exp(- Δη'²/2σ²)

Fit parameters vs Centrality classes:

ΔV{4} fit:

D and σ'

How do D and σ' calculate?

D: the average of all the points in 2D histogram

σ':
1. get slope in ΔV{4} fit = k*(Δη₁-Δη₂).
2. σ'(Δη)=k(2-|Δη|) = k(2-|η_α-η_β|)
3.<σ'>= Integral σ'(η_α from -1 to 1, η_β from -1 to 1)  / 4
σ'(η_α)=1/2 (3k-k η_α²)
<σ'>=4/3 k

V{2}, V{4}, D, σ' vs Centrality

σ' / <v> vs Centrality

Black: with sigma' and D subtracted
Blue: with D subtracted
Green: without subtraction
Pink: PRC 86, 014904 (2012) published curve

Only black one has sys. err. as grey band.
Others only plot stat. err.