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jet analysis

jet analysis. Dec.22/2008 ~. visible , without smear, |eta|<1, [0.1,0.1] cells, pp5500GeV. JET PROPERTIES. Celljet (the Jet-Finding Method). Parameters to input are “eTseed”, “coneRadius”, “Min-eT”. divide η-φ space in [0.1, 0.1] cells calculate transverse energy (eTcell) in each cell

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jet analysis

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  1. jet analysis Dec.22/2008 ~

  2. visible , without smear, |eta|<1, [0.1,0.1] cells, pp5500GeV JET PROPERTIES

  3. Celljet (the Jet-Finding Method) Parameters to input are “eTseed”, “coneRadius”, “Min-eT” divide η-φ space in [0.1, 0.1] cells calculate transverse energy (eTcell) in each cell select candidates of jet-seed by eTcell > ”eTseed” calculate sum of eTcell in the cone which center positioned at jet-seed (eTsum=ΣeTcell) requirement : eTsum>”Min-eT” define the survivors as found jets

  4. Distance btw primary parton and celljet center • assumption: • dr<1にprimary partonからのjetが入っている • dr<1に他のjetがない • dr<1の中でcelljet.eTが最大のjetをprimary parton起源のjetとした • celljet.coneradius = 1. • distance b/w primary parton & celljet center quark gluon photon proton proton parton found jet 80% integral(0~r) dr

  5. Distance btw celljet center and each tracks • assumption: • dr<1にprimary partonからのjetが入っている • dr<1に他のjetがない • dr<1の中でcelljet.eTが最大のjetをprimary parton起源のjetとした • celljet.coneradius = 1. • distance b/w celljet center & each tracks (eT weighted) quark gluon photon 80% integral(0~r)

  6. jet energy balance • dr(distance btw parton & celljet) • coneradius • qq/gg/γγ : jet2 energy/jet1 energy(jet2 energy<jet1 energy) • qγ/gγ : q/g jet energy/photon jet energy dr = 0.4, coneRadius=0.25 dr={0.45(quark),0.55(gluon),0.3(photon)}, coneradius=1.0 qq gg γγ qγ gγ

  7. visible/charged/neutral , with smear, |eta|<3, [0.1,0.1] cells, pp5500GeV, quark jet, dr<{0.45/0.55/0.30}, coneRadius=1.0, SINGLE JET ANALYSIS

  8. charged/neutral • MineTcharged = MineTvisible*2/3の確認 • energy fraction of each particle seed against with energy sum of generated particles MinBias pTHatMin=200GeV だいたいOK?

  9. influence by smear charged : TPC, Neutral : EMC particle energy(momentum) is smeared • assumption: • ALICE-EMC,TPC resolution • setting : • dr<0.45(quark)の中でcelljet.eTが最大のjet • dr<0.55(gluon)の中でcelljet.eTが最大のjet • dr<0.30(photon)の中でcelljet.eTが最大のjet • coneRadius=1.0 assume pion mass EMC TPC+ITS

  10. energy resolution • 見つけたcelljet-eT とjet-eT(parton-eT)の相関を作る • 直線Fitから補正係数を決定 • 見つけたcelljet-eTを補正したもの(E’)とjet-eT(parton-eT)(E)から(E’-E)/Eを計算 • resolution = (E’-E)/E分布のRMS eT-eT correlation resolution (E’-E)/E Profile

  11. jet energy resolution gluon jet resolution がquarkに比べよい? =>low-pT粒子でsmearingの桁落ち? visible resolutionがあまりによい =>計算違い? • setting: • visible : MineT = 20 GeV • charged : MineT = 20*2/3 GeV • neutral : MineT = 20*1/3 GeV • eTseed = 0.3 * MineT quark gluon photon なんだか怪しいが、計算ミスは見当たらない…

  12. parton energy resolution • setting: • visible : MineT = 20 GeV • charged : MineT = 20*2/3 GeV • neutral : MineT = 20*1/3 GeV • eTseed = 0.3 * MineT visibleで10~20%程度 ほとんどkinematicsで決まっている quark gluon photon 前pageと同じ計算なので少し自信がない…

  13. visible , |eta|<2, [0.1,0.1] cells, embedded jet : jet center eta < 1. coneradius = 1.0 quark jet (pp5500GeV からのB-to-B jet)+(HYDJET HD+J event), JET FINDING METHOD

  14. parameter selection(threshold/coneRadius) • BKG subtraction • eTcell(sum of eT in cell) < threshold を集めてくる • それらのcellを使いmean-eTを求める(mean-eT) • 全てのeTcellからmean-eTを引く • pythia-celljetと同じ作業 • threshold/coneRadiusはどの程度に設定すべきか? • (Ejet’-Ejet)/Ejetの幅が最小となる値を見つけたい jet energy resolution(0.1~0.75) coneRadius(0.05~0.5) threshold[GeV](0~22)

  15. 50GeV 100GeV threshold : 15GeV coneRadius : centralityの関数 150GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  16. parameter selection(Min-eT/eTseed) • S/(S+B) ≡ Nreal/Nfound • efficiency ≡ Nreal/Nembed Nreal : 見つかったpythiaからのB-to-B jetの数 Nfound : celljetで見つけたB-to-B jetの数 Nembed : 埋め込んだB-to-B jetの数 • S/(S+B), efficiencyの値からMin-eT, eTseedの最適化 • {S/(S+B)}*{efficiency} 隣のcellまで許容 energy resolution pythia B-to-B jet : dphi-PI 2sigma B-to-B jet の決め方/答え合わせ方法 |dφ-π|<0.38 dr(pythia-jet/found jet) < 0.11 1.-|Efound jet/Epythia jet| < 0.45 S/(S+B)(0~1) efficiency(0~1) {S/(S+B)}*{efficiency}(0~0.9) eTseed/Min-eT(0.1~0.9) Min-eT/pTHat(0.2~1.0)

  17. 50~100GeV S/(S+B) 100~150GeV 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  18. 50~100GeV efficiency 100~150GeV 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  19. 50~100GeV {S/(S+B)}*eff 100~150GeV Min-eT = 0.5*pTHat eTseed = 0.3*Min-eT 実際にはひとつの値しか使えない 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  20. jet(parton) energy resolution • coneRadius : function of centrality • threshold : 15GeV • Min-eT : pTHat * 0.5 • eTseed : 0.3 * Min-eT 上 : (pythia jet eT) vs (celljet eT(corrected)) 下 : (pythia parton eT) vs (celljet eT(corrected)) central peripheral

  21. jet(parton) energy resolution jet energy resolution parton energy resolution 100GeV jet energy resolution = 25%程度(central) 100GeV parton energy resolution = 25%程度(central)

  22. S/(S+B), efficiency, eff*S/(S+B) • S/(S+B) ≡ Nreal/Nfound • efficiency ≡ Nreal/Nembed Nreal : 見つかったpythiaからのB-to-B jetの数 Nfound : celljetで見つけたB-to-B jetの数 Nembed : 埋め込んだB-to-B jetの数 • Min-eT : pTHat * 0.5 • eTseed : 0.3 * Min-eT S/(S+B) efficiency {S/(S+B)}*eff

  23. jet energy balance • coneRadius でほぼ決定される(coneRadiusはjet resolutionで最適化されている) • quenching を入れたときの土台 • jet2 energy/jet1 energy(jet2 energy<jet1 energy) central peripheral

  24. plan • gluon jet, photon jet でも同様にconeRadius等の最適化 • gamma-jetのS/(S+B),efficiencyの計算 • gamma-jetのenergy balanceの計算 • (method dependence) • jet quenchingした上で、parton energy lossの計算(再現性能)

  25. BACK UP SLIDES

  26. PYTHIA jet resolutioncorrelation of jet eTcorrelation of parton/jet eT

  27. quark gluon photon jet-Not smeared visible charged neutral

  28. quark gluon photon jet-smeared visible charged neutral

  29. quark gluon photon parton-Not smeared visible charged neutral

  30. quark gluon photon parton- smeared visible charged neutral

  31. |dφ-π|<0.38dr(pythia-jet/found jet) < 0.111.-|Efound jet/Epythia jet| < 0.45

  32. 50~100GeV S/(S+B) 100~150GeV 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  33. 50~100GeV efficiency 100~150GeV 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  34. 50~100GeV {S/(S+B)}*eff 100~150GeV Min-eT = 0.5*pTHat eTseed = 0.3*Min-eT 実際にはひとつの値しか使えない 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  35. |dφ-π|<0.3dr(pythia-jet/found jet) < 0.111.-|Efound jet/Epythia jet| < 0.2

  36. 50~100GeV S/(S+B) 100~150GeV 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  37. 50~100GeV efficiency 100~150GeV 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

  38. 50~100GeV {S/(S+B)}*eff 100~150GeV 150~200GeV 0-10% 10-20% 20-30% 30-40% 40-50% 50-60% 60-75%

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