## June 28, 2002

First try at efficiency at 20 GeV -- PiMinus

First we ran submit.pl on the 3 directories Eric created ...

/auto/pdsfdv10/starprod/embedding/P02gd/Piminus_901_20GeV (and 902,
903)

The .root output files are in dir ...

/auto/pdsfdv41/starprod/QA/MiniDst/test/FullField/PiMinus/

(Manuel's macro doesn't consider the option of RevHalfField, and it
defaults to FullField. We'll change the directory name later.)

From those files we obtained the efficiency following Olga's
suggestions.The error in the efficiency was propagated from the stats of
both histograms. We understand that this is not quite the correct
procedure, since the histograms are not independent. Olga uses
err(eff)=sqrt(p(1-p)/N) ("binomial errors"), where N=number of particles
from MC input in each bin, p=reconstruction "efficiency" for the
corresponding bin. We'll correct the errors later.

Here are the first results

a)
histograms

Large circles: mMcTracks.mPtMc (0-2 GeV/c, 40 bins)... cuts A

Small circles: mMatchedPairs.mPtMc (0-2 GeV/c, 40 bins) ... cuts B

b)
efficiency

ratio... mMatchedPairs.mPtMc/mMcTracks.mPtMc

cuts A:

centCut= mNUncorrectedPrimaries>=237 (10% most central)

vtxCut= abs(mVertexZ)<30&&((mVertexX+0.246)^2+(mVertexY-0.378)^2)<1

eventCut = centCut+vtxCut

yCut=(asinh((mMcTracks.mPtMc/(1/sinh(mMcTracks.mEtaMc)))/sqrt(0.13956995^2+mMcTracks.mPtMc^2))>-.1)&&(asinh((mMcTracks.mPtMc/(1/sinh(mMcTracks.mEtaMc)))/sqrt(0.13956995^2+mMcTracks.mPtMc^2))<.1)

pCut= eventCut + yCut

Nevents= 1882 (NeventsTotal before event cuts = 57749 )

NMcTracks= 5771

cuts B:

centCut= mNUncorrectedPrimaries>=237 (10% most central)

vtxCut= abs(mVertexZ)<30&&((mVertexX+0.246)^2+(mVertexY-0.378)^2)<1

eventCut = centCut+vtxCut

yCut=(asinh((mMatchedPairs.mPtMc/(1/sinh(mMatchedPairs.mEtaMc)))/sqrt(0.13956995^2+mMatchedPairs.mPtMc^2))>-.1)&&(asinh((mMatchedPairs.mPtMc/(1/sinh(mMatchedPairs.mEtaMc)))/sqrt(0.13956995^2+mMatchedPairs.mPtMc^2))<.1)

hitsCut= mMatchedPairs.mFitPtst>=25&&mMatchedPairs.mNCommonHit>=10

dcaCut= mMatchedPairs.mDcaGl<=3

pCut= eventCut + yCut + hitsCut + dcaCut

Nevents= 1882 (NeventsTotal before event cuts = 57749 )

NMcTracks= 3673