Alice at LHC Jettiness and Reaction Plane determination at LHC University of Tsukuba Dousatsu Sakata Workshop at Wuhan 2008/12/4

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/42 Outline  HYDJET++(HYDJET)  Reaction Plane resolution  Jet Reconstruction  to be done...

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/43 HYDJET++(HYDJET) HYDJET++ is event generator for high energy heavy ion collision. HYDJET is previous one. Hard part: PYTHIA or PYQUEN (modifies PYTHIA6.4 for jet quench effect) Soft part: HYDJET++ (represents the ” thermal ” hadronic state FASTMC) Set Parameter (LHC default) A :207(Pb) CME : 5500GeV Set :hydro + pyquen hard(&quenching) soft pthatmin: 7.GeV/c nucl. shadowing : on T0 : 0.8GeV Tf :130MeV  :0.1fm/c Tc :170MeV # of flavor:0  tf :10fm/c max ly flow:4. max ty flow:1.1 unsure very peripheral |  |>3

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/44 Particle emission of HYDJET++ These figure are output of sample code of HYDJET++ to compare RHIC data and HYDJET++ Data RHIC AuAu 200GeV left: pT distribution right: rapidity distribution point : data from STAR point: data from PHOBOS black line: HYDJET++ black line: HYDJET++

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/45 Reaction Plane resolution PxPx PyPy PzPz Reaction plane A:  >0 B:  <0 pT cut for RP <2GeV/c ITS+TPC(pT wight) have a good Reaction Plane resolution. HYDJET [hydro+pythia] ITS+TPC V0 T0 -0.9<  < <  < <  < <  < <  < <  < <  < 6.0 FMD pT weight

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/46 Compare mesured-v2 and true-v2  1 ratio= mesuredv2 /truev2 [truev2: v2 with respect to true RP] No pT dependence we have to minimize non-flow contribution ptcut for RP : 3GeV/c centrality 20-40%

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/47 Method for the Reconstruction Purpose estimate R & parton pT dependence of eTjet/eTpart & resolution Data set PYTHIA - hardQCD:all on softQCD:all off - primary parton Pt :20-200GeV/c(20GeV/c step) HYDJET++ - LHC default  Find seed particle find highest eT track (only a particle par event)  Sum up eT in Cone (eTjet)  Compare parton eT (eTpart) calculate eTjet/eTpart Primary parton seed particle Cone Radius Figure PYTHIA (hard only) pThat GeV/c

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/48 Jet Reconstruction (PYTHIA) distribution of eTjet/eTpart (R=0.4) R dependence of eTjet/eTpart&resolution pThat dependence of eTjet/eTpart&resolution(R=0.4) eTjet/eTpart & resolution are better when R is larger, and the larger pT of primary parton also makes resolution better. at pthat=40 eTjet/eTpart~0.9 resolution[RMS/Mean] < 20% color : differential pT of primary parton [20-200GeV/c(20GeV/c step)] R=0.4

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/49 Soft and Hard particle in HYDJET++ Almost particles comes from hard collision in eT>8GeV In eT>3GeV, particles come from hard more than soft.

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/410 Jet Reconstruction (HYDJET++) we like to get information of jet. So we estimate R dependence of hard eT ratio. seed eT cut [eTcut=0]CentralityeT cut [seedeTcut=0] Smaller R is better to get information of Jets. Yaxis:  eThard/  eTall Xaxis: cone radius R setting HYDJET++ [HYDJET++ & PYQUEN]

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/411 Combine PYTHIA & HYDJET++ HYDJET++ (soft) PYTHIA (hard) HYDJET++&PYTHIA  -  distribution Radius direction:  [-10<  <10] Anguler direction:  [ -  <  <  ] Hight direction: pT[GeV/c] To analyze jets with information of primary parton. Mix hard event of PYTHIA and soft event of HYDJET++

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/412 To be done...  F ind & reconstructjets in HYDJET++ with di-jets.  Estimate # of jets at # of Ncol. And mix HYDJET++.  F ix cut parameter to reconstruct & find jets  Include Detector effects.  Estimate trigger rate,efficiency, ・・・

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/413 Conclusion  E stimate RP resolution & compare v2 and true-v2  T est of simple reconstruction - PYTHIA eTjet/eTpart~0.9 resolution<20% at pThat=40GeV/c larger R is better to reconstruct jets - HYDJET++ smaller R is better to find jets and seed particle in eT>8GeV/c is almost come from hard collision in eT > 3GeV/c particles in cone come from hard more than soft And we have to do much more work ！

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/414 Backup

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/415 ALICE detector ITS V0 T0 FMD -0.9<η< <η< <η< <η< <η< <η< <η< 6.0

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/416 Pt & Et of primaly parton & seed particle violet : parton pT or eT other color : trigger particle pT or eT

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/417 Particle distribution of jet axis HYDJET++ hard ratio vs R PYTHIA particle distribution vs dφ dφ= φ- φparton

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/418 Detail of jet reconstruct R=0.4

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/419

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/420 Njet correlation

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/421 Introduction 3 Reaction Plane Reaction plane X Z Y PxPx PyPy PzPz

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/422 Method 6 x y x y Ψ φ

Alice at LHC Dosuatsu SakataWork shop at Wuhan 2008/12/423