I run the bfc chain with the new version of StiIstDetectorBuilder from Willie.

library : starnew

bfc chain : trs,ssd,upgr15,pixFastSim,Idst,IAna,l0,tpcI,fcf,Tree,logger,ITTF,Sti,StiRnd,PixelIT,IstIT,StiPulls,genvtx,NoSvtIt,SsdIt,MakeEvent,McEvent,geant,evout,IdTruth,bbcSim,emcY2,EEfs,big,-dstout,fzin,-McEvOut,clearmem,MiniMcMk,McAss,McAna

file :/star/institutions/emn/bouchet/newGeom/100Ev_800pionsplus.fzd

It has 800 pions + per event with :

• 0.1 < pT < 5.0
• |eta| <1
• 0< phi <2*pi
• |z| <30 cm
• vertex at 0.0.0.

section 1 :

I used a StAnalysisMaker to fill the events characteristics, such as number of TPC,SSD,pixel and IST hits, good globals and primaries.

It has minimal cuts :

• |z_vertex| < 10 cm
• NTpcFit >15 

From this, I plotted next the r/phi vs Z positions of hits used in tracking

I have, after cuts, 69176 tracks.

The following table describes the tracks population (per detector)

Section 2 :

From the output of the job, i used the MuDst.root file.

I modified the macro from Yuri (MuSvt) to run over this file : basically, it loops over primary tracks (after cuts selection) and we can plot some properties of the StMuTrack class, such as the number of possible, fitted hits.

I also used this macro to plot the dca resolution (in xy and Z) vs 1/P.

The possible and fitted hits are accessible via :

• Int_t NoFIstHits = (mNHitsFitInner[k] & 0x7);
• Int_t NoFSsdHits = ((mNHitsFitInner[k] >> 3) & 0x3);
• Int_t NoPIstHits = (mNHitsPossInner[k] & 0x7);
• Int_t NoPSsdHits = ((mNHitsPossInner[k] >> 3) & 0x3);
• Int_t NoFPxlHits = ((mNHitsFitInner[k] >> 5) & 0x7);
• Int_t NoPPxlHits = ((mNHitsPossInner[k] >> 5) & 0x7);

Fig 3 : pixel

An estimation for each detector consists to take the ratio of tracks having NPossible = NFitted over all tracks for NPossible_expected to respect with this detector

Remember that I used the slow simulator for the SSD, it may explain the lower efficiency compared to the ist and pixel.

Finally, I plotted the dca resolution in XY and Z direction

Fig 4 : sigma_dca_xy vs 1/p

Fig 5 : sigma_dca_z vs 1/P

At P = 1 GeV/c, the dca resolution is XY and Z is less than 25 um for tracks having 1 ssd hit + 1 ist hit + 2 pixel hits. 

section 3 :

I tried to run with the latest library (SL08e)

The following plots are the number of Possible hits vs. the number of fitted hits for ssd, ist and pixel detectors.

I used the same macros (then same cuts) as in section 2 (where it was with SL08d)

Fig. 6 : ssd

Fig. 7 : ist 

 Fig. 8 : pixel

The differences between SL08e and SL08d are :

• number of tracks with SL08d : 70035
• number of tracks with SL08e : 70022

However, the distribution look the same