Di-jet simulationDi-jet simulation

Hiroki YokoyamaUniv. of TSUKUBAALICE POST-QM09

MotivationMotivationDijet phi balanceDijet energy balance

2

Dijet Phi-Balance resolution Dijet Phi-Balance resolution pp5500GeVpp5500GeV

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

Dijet Energy Balance Dijet Energy Balance pp pp 5500GeV5500GeV

PYTHIA8 simulation CellJet algorithm

◦ R=0.2

Dijet energy balance =

Including detector energy smearing

€

ET1 − ET

2

1 2 ⋅(ET1 + ET

2 )

Resolution of Dijet energy balance is improved by J-Cal

TPC-TPC

TPC-EMC

JCal-EMC

γ-jet:JCal-EMC

with all particles

€

ET1 − ET

2

1 2 ⋅(ET1 + ET

2 )

R=0.7 Red: Quench OffBlue: Quench On

R=0.2ETmean=100GeV

PYQUEN PYQUEN pp5500GeVpp5500GeV

PYTHIA6+Jet-Quenching

5

20GeV energy loss at central collisionEnergy unbalance

•pTHat=100GeV•5% central

SummarySummaryPYTHIA8 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

BACKUPBACKUP

7

jet energy balance/dphi resolution with jet energy balance/dphi resolution with PYTHIA8PYTHIA8 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

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 jet energy balance/dphi resolution with PYQUENPYQUEN

R=0.2100GeV dijet