void llbar_ana_task(int nevts=0)
{				
	// *** the files coming from the simulation
	TString pre = "dpm";
	bool signal = false;
	TString inPidFile = pre+"_pid.root";    // this file contains the PndPidCandidates and McTruth
	TString inRecoFile  = pre+"_reco.root";
	TString inSimFile = pre+"_sim.root";  // this file contains the MC truth
	TString inParFile = pre+"_par.root";
	
	// *** the output file
	TString OutFile="output_"+pre+"_ana_task.root";
	
	// *** PID table with selection thresholds; can be modified by the user
	TString pidParFile = TString(gSystem->Getenv("VMCWORKDIR"))+"/macro/params/all.par";	

	// *** initialization
	FairLogger::GetLogger()->SetLogToFile(kFALSE);
	FairRunAna* fRun = new FairRunAna();
	FairRuntimeDb* rtdb = fRun->GetRuntimeDb();
	fRun->SetInputFile(inPidFile);
	
	// *** setup parameter database 	
	FairParRootFileIo* parIO = new FairParRootFileIo();
	parIO->open(inParFile);
	FairParAsciiFileIo* parIOPid = new FairParAsciiFileIo();
	parIOPid->open(pidParFile.Data(),"in");
	
	rtdb->setFirstInput(parIO);
	rtdb->setSecondInput(parIOPid);
	rtdb->setOutput(parIO);  
	
	fRun->SetOutputFile(OutFile);
	
	// *** HERE OUR TASK GOES!
	PndLLbarAnaTask *anaTask = new PndLLbarAnaTask();
	//PndLLbarAnaTask_DecayTreeFit *anaTask = new PndLLbarAnaTask_DecayTreeFit();
	anaTask->SetBeamMom(1.642);
	anaTask->SetIsSig(signal);
	fRun->AddTask(anaTask);
	
	// *** and run analysis
	fRun->Init(); 
	fRun->Run(0,nevts);

	if (gROOT->GetVersionInt() >= 60602) {
		gGeoManager->GetListOfVolumes()->Delete();
		gGeoManager->GetListOfShapes()->Delete();
		delete gGeoManager;
	}
}