1. Di-jet simulation Hiroki Yokoyama Univ. of TSUKUBA ALICE POST-QM09

2. Motivation Dijet phi balance Dijet energy balance 2

3. Dijet Phi-Balance resolution pp5500GeV 3 PYTHIA8 simulation CellJet algorithm ◦ R=0.2 Dijet phi balance = dphi - π Including detector energy smearing High energy Dijet have clean back-to-back shape High energy Dijet have clean back-to-back shape

4. Dijet Energy Balance pp 5500GeV PYTHIA8 simulation CellJet algorithm ◦ R=0.2 Dijet energy balance = Including detector energy smearing Resolution of Dijet energy balance is improved by J-Cal TPC-TPC TPC-EMC JCal-EMC γ-jet:JCal-EMC with all particles

5. R=0.7 Red: Quench Off Blue: Quench On R=0.2 E Tmean =100GeV PYQUEN pp5500GeV PYTHIA6+Jet-Quenching 5 20GeV energy loss at central collision Energy unbalance 20GeV energy loss at central collision Energy unbalance pTHat=100GeV 5% central

6. Summary PYTHIA8 simulation ◦ High energy jets make clean Back-to-Back ◦ The energy balance resolution is improved when J-cal is installed PYQUEN simulation ◦ ~20GeV energy loss at central collision ◦ energy unbalanced 6

7. BACKUP 7

8. jet energy balance/dphi resolution with PYTHIA8 btob jet selection ◦ HardQCD::all = on ◦ pp5500GeV ◦ CellJet(MineT=20(13), eTseed=1.5(1.), coneRadius=0.2) ◦ [0.1,0.1] cell (|eta|<5.), particle ET(p) smearing by detector resolution ◦ cellJet.size()==2 ◦ phi1>0 && phi2<0 pTHat(40~180GeV) configuration (TPC-TPC, TPC-(EMC+TPC), (EMC+TPC)-(EMC+TPC)) energy correction (in case TPC-(EMC+TPC) conf.) 8

9. 9 btob jet selection ◦ pp5500GeV ◦ CellJet(MineT=20, eTseed=2., coneRadius=0.2, pTcut=0) ◦ [0.1,0.1] cell (|eta|<5.), particle ◦ cellJet.size()==2 each pTHat(20~100GeV) EMC+TPC particles each configuration (w/o JQ, with JQ(4fm)) jet energy balance/dphi resolution with PYQUEN R=0.2 100GeV dijet