Simulation hijing events (240 processed) with SST in tracking :

export BFC_OPTIONS='"y2014a,event,McEvent,MuDst,tpc,fzin,sim_T,gen_T,geantout,tpcrs,TpcHitMover,TpxClu,evout,-HitFilt,FieldOn,AgML,usexgeom,MakeEvent,ITTF,Sti,NoSsdIt,
NoSvtIt,StiHftC,pxlFastSim,istFastSim,sstDb,sstfast,Idst,BAna,l0,Tree,logger,genvtx,tpcDB,bbcSim,btofsim,tags,emcY2,EEfs,evout,-dstout,IdTruth,big,McEvout,MiniMcMk,
StiPulls,ReadAll,clearmem"'
export BFC_INPFILE='"/star/institutions/lbl_prod/mlomnitz/Hijing_FullProd_10302015/hijing/fz_out_0_1k/hijing_'$1'.starsim.fzd"'

default : hit errors in r/phi = 30 microns
test : hit errors in r/phi = 100 microns

It is done by running with a local StarDb where the ssdHitErrors are changed :

StarDb_test/Calibrations/tracker/ssdHitError.20130101.000001.C

TDataSet *CreateTable() { 
if (!gROOT->GetClass("St_HitError")) return 0;
HitError_st row;
St_HitError *tableSet = new St_HitError("ssdHitError",1);
Double_t sigma_x = 0.010;
Double_t sigma_z = 0.0857;
memset(&row,0,tableSet->GetRowSize());
//                                        hit errors are squared !
row.coeff[0]	 =   sigma_x*sigma_x;     // u intrinsic;
row.coeff[1]	 =   0.0;      // u cross;
row.coeff[2]	 =   0.0;      // u drift;
row.coeff[3]	 =   sigma_z*sigma_z;     // z intrinsic;
row.coeff[4]	 =   0.0;      // z dip;
row.coeff[5]	 =   0.0;      // z drift;
tableSet->AddAt(&row);
// ----------------- end of code ---------------
return (TDataSet *)tableSet;
}

BaseQA plots here

--> there are almost no differences in the tracking when using the increased hit errors.
In fact there are only a couple of tracks difference with the 2 samples : TPC RC vs MC hits (default) vs TPC RC vs MC hits (test) 

Compared to 45 TPC hits, the single SSD hit has ~ no weight in the overall QA tracking

BaseQA plots details.

1) Run over 2.4k events over plain hijing :
Comparison SSD=1, whatever PXL and IST : here
Comparison SSD=1, whatever PXL and IST=0 : here
Comparison SSD=1, PXL=1 (inner) and IST=1 : here
Comparison SSD=1, PXL=1 (outer) and IST=1 : here


2) Run over 1k events of hijing mixed with PileUp, as explained by Jason :

y2014a geometry
40k events 
200 GeV AuAu hijing events
minbias 0 < b < Rmax 
sigma_z = 30 cm

fzd files only --
/star/data99/reco/AuAu200/hijing_382/b0_20/minbias/y2014a/gheisha_on/gstardata/*.background.fzd


Sample 2: used as physics "trigger" sample

y2014a geometry
20k events
200 GeV AuAu hijing events
minbias 0 < b < Rmax
sigma_z = 30 cm
VERTEX CUT |z| < 6 cm

fzd files only (hit and possibly full reconstruction pending)--
/star/data99/reco/AuAu200/hijing_382/b0_20/minbias/y2014a/gheisha_on/gstar_pileup_Oct05/*.trigger.fzd


Sample 3: pileup files

y2014a geometry
Sample 1 merged with sample 2
0.5% probability of interaction in each bxing (corresponds to ~50 kHz mb)
TPC samples 376 bxings before, 1 during, and 376 after the trigger
PXL samples 875 bxings before, 1 during, and 875 after the trigger

Comparison SSD=1, whatever PXL and IST : here