In order to correct for dectector acceptance, Monte Carlo simulations have been embedded into the data and passed through reconstruction in order to determine the particle efficiencies. The efficiency is (#MC Tracks Reconstructed)/(#MC Tracks Total). The following function is used to fit the efficiencies:

Efficiency = A exp[-(b/pt)c] + d(pt)

At multiplicities much lower than Au+Au collisions at 200 GeV, the Cu+Cu 22 GeV collisions have negligible variation in efficiency by centrality. Thus the min-bias efficiencies are used for all centralities.

For Reference the Cu+Cu 62.4 GeV Refmult borders are given below in comparison with Au+Au 200 GeV

Centrality Refmult Borders

Centrality	CuCu22 Refmult	AuAu200 Refmult
top edge	~155	~720
5%	≥ 86	≥ 510
10%	≥ 72	≥ 431
20%	≥ 51	≥ 312
30%	≥ 35	≥ 217
40%	≥ 24	≥ 146
50%	≥ 16	≥ 94
60%	≥ 10	≥ 56
70%	≥ 6	≥ 30
80%	≥ 4	≥ 14

The embedding used is from the Cu+Cu 62.4 GeV Dataset for π±, K+, and for protons. The K+ minbias efficiency has been used for K- as well. As a the Au+Au 200 GeV embedding from Run 5 for K- is shown to demonstrate that there is negligible difference between K+ and K- efficiencies (even in a different collision - as long as the appropriate refmult cuts are made).

Since the K+ and K- efficiencies demonstrate that there is negligible difference at these multiplicities even between Cu+Cu 62.4 GeV and Au+Au 200 GeV the latter is used for the p efficiency.

[Note: While there was embedding available for the Cu+Cu 200GeV Dataset, it was not used since it employes an updated tracker in reconstruction which wasn't used in the Cu+Cu 22 GeV dataset.]

Embedding used for Efficiency

Particle	Data Set
π+	≥ 86
π-	≥ 72
K+	≥ 51
K-	≥ 35
p	≥ 24
p	≥ 16
60%	≥ 10
70%	≥ 6
80%	≥ 4

Primary Tracks have been corrected for energy loss in material (mostly before reaching the TPC) with the pion mass assumption. For Kaons, protons and antiprotons, futher correction is needed.