“DijetAnalyzer”

• A simple Java analysis routine that is called for each event

  • Checks if there are reconstructed “Jet” objects available
  • Sums the transverse energy in the Jets
  • Selects candidate Jets with transverse energy > 15 GeV
  • If there are >= 2 of these, computes the effective mass, Pt, etc.

• JAS with the Objy interface processes ~25 events per second

public void processEvent(final EventData d) {

final CMSEventData data = (CMSEventData) d;

final double ET_THRESHOLD = 15.0;

Jet jets[] = new Jet[2];

Iterator jetItr = (Iterator) data.getObject("Jet");

if(jetItr == null) return;

int nJets = 0;

double sumET = 0.;

FourVectorRecObj sum4v = new FourVectorRecObj(0.,0.,0.,0.);

while(jetItr.hasMoreElements()) {

Jet jet = (Jet) jetItr.nextElement();

sum4v.add(jet);

double jetET = jet.ET();

sumET += jetET;

if(jetET > ET_THRESHOLD) {

if(nJets <= 1) {

jets[nJets] = jet;

nJets++;

}

}

}

njetHist.fill( nJets );

if(nJets >= 2) { // dijet event!

FourVectorRecObj dijet4v = jets[0];

dijet4v.add( jets[1] );

massHist.fill( dijet4v.get_mass() );

sumetHist.fill( sumET );

missetHist.fill( sum4v.pt() );

et1vset2Hist.fill( jets[0].ET(), jets[1].ET() );

}

}

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