This is a QA for a pions sample produced when bug #1568 ("A dip of pseudorapidity distribution in embedding outputs") was fixed. There is however other issue. In the StMiniMcTree, in the mMatchedPairs branch, there are tracks with mMatchedPairs.mNCommonHit>9, mMatchedPairs.mPtPr = 0.0 and mMatchedPairs.mEtaPr = 0 (please see fig. 1, 2 and 3).

To check if the problem is with the simulations or StMiniMcMaker, I have run StAssociationMaker by my own and find out that there are no track with mNCommonHit>9 and eta = 0 and pT = 0. So far the conclusion is the problem is with production of minimc files.

Fig. 1 StMiniMc: All reconstructed tracks with nCommon hits > 0: StMiniMcTree->Draw("mMatchedPairs.mEtaPr","mMatchedPairs.mNCommonHit>9")
 

Fig. 2 StMiniMc: All reconstructed tracks with nCommon hits > 0: StMiniMcTree->Draw("mMatchedPairs.mEtaPr","mMatchedPairs.mPtPr == 0 && mMatchedPairs.mNCommonHit>9")
 

Fig. 3 StMiniMc: All reconstructed tracks with nCommon hits > 0: StMiniMcTree->Draw("mMatchedPairs.mEtaPr","mMatchedPairs.mPtPr > 0 && mMatchedPairs.mNCommonHit>9")
 

Fig. 4 My own association: eta distribution for all reconstructed tracks with nCommon hits > 9.
 

Fig. 1 My own association: pT distribution for all reconstructed tracks with nCommon hits > 9.