void ana_task_fast(TString InPrefix="test", TString OutPrefix="test", int nevts=0,  double pbarmom = 6.56903, TString mode = "L", double pidcut=0, bool fast=true, bool fit=false, bool save=false)
{

        double mp=0.938272;
        double xx = (2*mp)*sqrt(pbarmom*pbarmom+mp*mp) + (2*mp*mp);
        double sqrts = sqrt(xx); 
        TDatabasePDG::Instance()->AddParticle("pbarpSystem0","ppbar0",sqrts,0,0.0001,0,"",88880);
        TDatabasePDG::Instance()->AddParticle("pbarpSystem","ppbar",sqrts,0,0.0001,0,"",88888);
	TDatabasePDG::Instance()->AddParticle("psi(3770)","psi(3770)",sqrts,0,0.0001,0,"",30443);

	
	// *** the in output file for FairRunAna
	TString InFile = InPrefix+"_fast.root";  
        TString set="";
	if(pidcut==0)     set="1";
	if(pidcut==0.1)   set="2";
	if(pidcut==0.25)  set="3";
	if(pidcut==0.5)   set="4";
	if(pidcut==0.95)  set="5";


	TString OutFile = OutPrefix+"_task"+set+".root";  
	TString OutFile_dummy = OutPrefix+"_dummy";  
					
	// *** initialization
	FairLogger::GetLogger()->SetLogToFile(kFALSE);

	FairRunAna* fRun = new FairRunAna();
	fRun->SetWriteRunInfoFile(kFALSE);
	fRun->SetInputFile(InFile);
	fRun->SetOutputFile(OutFile);

	// *** take constant field; needed for PocaVtx
	RhoCalculationTools::ForceConstantBz(20.0);

	// *** HERE OUR ANALYSIS TASK GOES!
	PndScrutAnaTask *scrutTask = new PndScrutAnaTask(pbarmom, OutFile, mode, pidcut, fast, fit, save);
	fRun->AddTask(scrutTask);

	// *** and run analysis
	fRun->Init(); 
	fRun->Run(0,nevts);	
}