, A, A, A,,,, A @ 4988pSK
Large Hadron Collider (LHC) CERN Run (-) - 5.fb - @7TeV,.3fb - @8TeV (ATLAS) Run (5- ) - 3, 4TeV () - L = fb - (~8) - L = 3fb - (~; Run3 ) - pileup Run Run 7-8 TeV 3-4 TeV 5 ns 5 ns.77 34 cm - s - - 34 cm - s - 9- -6
ATLAS Experiment ATLAS 44m, m, 7t - Inner detectors : Si pixel, SCT, TRT - LAr sampling EM calorimeter - Tile scintillator hadron calorimeter - Toroidal magnet - Muon spectrometer Run Run Insertable B-Layer - ( IBL ) b-tagging 3
the Higgses mix with doublet messengers.. In this case, the running below MS is modified by the light superpartners, and the preferred scalar mass scale for a 5 GeV Higgs can be even larger [4 44]. Higgs mass (mh) vs SUSY scale (Ms) ACKNOWLEDGMENTS Run Gaugino 探索のモチベーション P. Draper arxiv::368 Appendix A: Comments on heavy SUSY scenarios 一方で - gaugino には Higgs mass Although we have focused on からの制限は弱い mixed stops which can - Run 3 5 stop/sbottom 5 mixingがない場合 Motivation Motivation ヒッグス粒子質量の 自然さ からの要請で トップ粒子の 5 ヒッグス粒子質量の 自然さ からの要請で ト 超対称性パートナー (スカラートップ=stop)の質量は軽くなる 超対称性パートナー be light enough to be produced at the LHC, let us briefly 5 (スカラートップ=stop)の 5 consider the case of stops without mixing. For small mhiggs Neutralino DMを信じるとEW gauginoは比較的軽い Higgs質量 mhiggs = mbare + MS @TeVD MS, we can compute the Higgs mass with FeynHiggs. For larger MS, we use a one-loop RGE to evolve the SUSY quartic down to the electroweak scale, computing gauginoにfocusした解析がいよいよ重要 the physical Higgs mass by including self-energy corrections [38, 39]. In Figure 6, we plot the resulting value of mh as a function of MS, in the case of zero mixing. We plot the FeynHiggs output only up to 3 TeV, at which point its uncertainties become large and the RGE is more Gaugino探索 trustworthy. One can see from the plot that accommo- Electroweak Strong Higgs質量 mhiggs = mbare + mhiggs FIG. 6. Higgs mass as a function of MS, with Xt =. The green band is theキャンセル output of FeynHiggs together with its asキャンセル sociated uncertainty. The blue line represents -loop renormalization in the StandardSUSY Model matched SM group evolution to the MSSM at MS.SM The blue bands give estimates of errors from varying the top mass between 7 and 74 GeV (darker band) and the renormalization scale between mt / and mt Fine tuning (lighter band). - レプトンを使ったinclusive EW gaugino探索 - 4年9月7日水曜日 35 mh @GeVD We would like to thank Michael Dine, Jared Evans, Howie Haber, Yevgeny Kats and Chang-Soon Park for useful discussions. PD is supported by the DOE unrun からの重要なinput der grant DE-FG-4ER486. The work of PM is supported in part by NSF CAREER Award NSF-PHY- Higgsは重い (5GeV) naiveにはsquark ~TeV 56833. MR is supported by the Fundamental Laws Initiative of the Center for the Fundamental Laws of Nature, Harvard University. The research of DS was supported in part by a DOE Early Career Award. - 実際探したらやっぱり重い (mq~ >TeV) (本講演) mt<6ge ~ (軽いstopがあるとしたら)なぜ見つからないのか? (軽いstopがあるとしたら)なぜ見つからな 消失飛跡を用いた長寿命winoの探索 (8pSK3; 斉藤) 実験的に観測が難しいシチュエーションにある可能性 実験的に観測が難しいシチュエーションに を考える を考える - Gluino pair production (8pSK; 南) 4
χ χ± Mχ± = Mχを仮定 ターゲット質量領域とRunの結果 ΔM - 最も軽い / 番目に軽いgauginoの質量差 χ モデルで比較的狭いmass gapが必要 9 8 (LSP: Lightest SUSY Particle) overclosure回避のために 多くの - LSPが暗黒物質 m( ) [GeV] がほとんど現象を決める 7 6 Run - Analysis strategyがよくない ΔMの大きい領域で感度を最適化 - 最近は ΔM<5GeV にて新しい解析 5 ターゲット領域 4 (ΔM < Mχ±/3) 3 Run (8pSK; 永井 3 4 5 6 7 8 9 ± m( ) [GeV] 本研究の目標 ターゲット領域で感度を持つように解析を改良 4年9月7日水曜日 5
Signal Chargino-neutralino χ ± χ WZ ll l signal: 3leptons + MET (Missing ET) phase spacewz Background q W q ν cross-section χ ± χ (Mχ± GeV) ~ pb - q Z χ ± χ (Mχ± 4GeV) ~. pb - SM WZ ~ 5 pb - 6
MET Missing base: MET / MT - ΔM ΔM, χ χ Missing pileuprunmet MET var: 4 cat: cut: optnj: SM WZ --- χχ (,5) --- χχ (3,) L=3fb - Missing MET, MT 3 (MC simulation) MET - 3 4 5 6 MET (GeV) 7
Event samples (signal/background) - Generator: Herwig++, 4TeV - Run smearing lepton, jetfull simulation Missing smearvisible object (leptons, jets) SFOS lepton pair (Same Flavor Opposite Sign) Baseline cuts. (i : iptlepton(e,μ)) single- / di- / tri-lepton trigger pt(l) > 3 or pt(l) > or pt(l3) > 5 (GeV) 4. MET > 3 GeV 5. msfos > 5 GeV ΔM > 5GeV. lepton pt>gev, η <.5 3. N(lepton)==3. 8
var: 66 cat: (MC cut: simulation) optnj: cosθ*w SignalbackgroundWZ θ*w: WZ Wpolar angle () 6 5 4 3 SM WZ --- χχ (,5) 5 --- χχ (3,) L=3fb - (SM WZ) t/u (χχ) squarkχ ± χ s (+αcos θ) - -.8 -.6 -.4 -...4.6.8 cosθ*w q s-chn. W q t-chn. W q u-chn. W (t/uχ ± χ ) squark q W * Z q q Z q q Z q ~ χ ± q~ d / q m q d d / + cos s d d / u t + t u / + cos ~ cos q ~ χ θ * W: WZ. W4 W lν 9
MT constraint method : var: 7 cat: cut: optnj: 9 8 7 6 5 4 SM WZ --- χχ (,5) 8 --- χχ (3,) 8 L=3fb - MT (lw, ν) = MW (off-shellmsfos) 3 WZpT balance: pt(w) = pt(z) - -8-6 -4-4 6 8 pt(w) - pt(z) (GeV) νw: Mν = Minv(lw, ν) = Mw (off-shellmsfos) 4 ν4 vector biascosθ*w - 3lepton Jet, MET cosθ*w var: 67 cat: cut: optnj: 7 6 5 4 3 - -.8 -.6 -.4 -...4.6.8 reco. cosθ*w
var: cosθ 67 * W cat: cut: optnj: 7 ΔMMz(9GeV)signal region 6 5 -.7.7 Off-shell Z : 5GeV< msfos <8GeV METsignal region 4 3 cosθ * W msfos ( bins) - -.8 -.6 -.4 -...4.6.8 On-shell Z (8GeV< msfos <GeV) (MET / MT) θ*w Run signal regions New cosθ * W =.7 8 bin
Shape Fit - Background: 3% - bin: ) (GeV) m ( Significance ratio (/) myana3 test_offs/nominal nominal_offs L=3fb 3 5 5 - (L=3fb - ).5.5 optimistic 5.5 5 5 3 35 4 m ( ± ) (GeV) : msfos / MET / MT3 bin
L=3fb - black: Run like analysis red: my analysis L=3fb - ~5GeVgain ) (GeV) m ( 95% CL limit (L = (L=3fb - ) 3 5 5 s=4tev m > m - ) m = m + m Z m = m ) (GeV) m ( Discovery 3σ sensitivity reach (L (3) = 3fb (L=3fb - ) 3 5 5 s=4tev m > m m = m - + m Z ) m = m 5 5 5 5 3 35 4 m ( ± ) (GeV) 5 5 3 35 4 m ( ± ) (GeV) 3
(Mχ ± ) 3fb - (~3) 3fb - (~3?) 95% CL 35 GeV 7 GeV 3σ sensitivity 3 GeV 55 GeV 95% CL limit (L=3fb (L=3fb - ) - ) Discovery 3σ sensitivity reach (L(3) = 3fb (L=3fb - ) - ) ) (GeV) m ( 45 4 35 3 5 s=4tev m > m m = m + m Z m = m ) (GeV) m ( 45 4 35 3 5 s=4tev m > m m = m + m Z m = m 5 my analysis 5 my analysis 5 Run 95%CL@.3fb - 5 Run 95%CL@.3fb - 5 5 3 35 4 45 5 55 m ( ± ) (GeV) 5 5 3 35 4 45 5 55 m ( ± ) (GeV) 4
LHC Run Higgs massrun gaugino gaugino SignalbackgroundMET ~ 5GeV @3fb - ~ 35GeV @3fb - ~ 7GeV @3fb - -, - (ΔM < 5GeV) 5
6
Run Type HLT Item Rate (Hz) Unique Rate (Hz) L Single µ mu6 imedium 54 MU mu5 36 8 MU mu6 msonly eta5 5 5 MU Di-muon mu4 34 9 MU mu4 mu8nol 9 MU (mu iloose mu8nol?)?? MU Tri-muon mu4 mu4nol MU (mu iloose mu4nol?)?? MU 3mu6 msonly 3MU6 3mu6 3MU6 e/ -muon e7 medium mu 7 7 EM5VH MU e medium mu EM8VH MU e medium mu8 EM8VH MU6 mu4 e7 medium MU mu4 g5 medium 7 7 MU g loose munol?? EM5VH mu msonly g loose 3 3 EM8VH MU6 Total for muons 338±3 Single e/ e8 tight iloose 6 6 EM4VHI e6 medium 7 3 EM5 g4 loose 34 3 EM5 g/3 loose PS to Hz each EM g4/5 loose PS to Hz each EMV g6/8// loose PS to Hz each EM5 Di e/ e7 loose 8 8 EM5VH g35 medium g5 medium 8 8 EM5VH g tight (iloose?)?? EM5VH e4 medium g5 medium?? EM5VH e medium g35 loose?? EM5VH Tri e e8 e9 medium (iloose?)?? 3EM7V EM5VH 3g loose?? EM5VH e medium g loose?? EM5VH Total for electrons 8±4 7
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Ω DM h ) [GeV] mass( 9 8 7 6 5 M /M =.5(mSUGRA) 4 M /M =.7 4 ) [GeV] mass( 9 8 7 6 5 4 4 3-3 - 3 4 5 6 7 mass( 8 9 ± ) [GeV] - 3 4 5 6 7 mass( 8 9 ± ) [GeV] - 9
M /M =.5(mSUGRA) 4 M /M =.7 4 9 8 7 6 5 4 3 3 4 5 6 7 8 9.9.8.7.6.5.4.3.. 9 8 7 6 5 4 3 3 4 5 6 7 8 9.9.8.7.6.5.4.3..
production 探索チャネル - 断面積大 --- pp χ±χ対生成 - 感度高い --- 3レプトン終状態 strong prod.+カスケード崩壊 EW direct production Chargino: χ± χ± Neutralino: χ χ χ3 χ4 Chargino-neutralino production (3L)- ATL 重い 重い Chargino-neutralino p - sleptonは重たい --- WZ or Wh 感度の高いWZを経由するモードに着目 3-lepton channel has sensitivity to chargino-neutralino pro First search for elec through intermediate sleptonsdecay or gauge bo sleptonが軽いとき (ml~ < Δm) / / Wino-li / Chargino-neutralino production (L)- ATLAS-CONF-3-93 in sn slepton経由 p Simplified model - χ±, χ : pure wino - χ : pure bino - Br (χ± Wχ) = Br (χ Zχ) = p stau経由 ` ± p p ` ` ` p p ± W ± Z ` / ` Si 5 degene Interm As flavour ratiosant / de ± signal : The selection requirements for the regions. All regions are mutu production Decays Hot off the press- this wastable the first LHC search for ` / ` require exactly three signal leptons and a same-flavour opposite-sign (SFOS)% leptonb or a SFOS lepton pair with mass less3! than GeV are rejected. The massof th with decays viab-jet Higgsreleased August! sleptonが重いとき (ml~ > Δm) ± closest the msfos. The calculated from the ETmisre m(, ) > m( e L, µ Lto,, Z-boson )> m(mass ) is denoted T is m(l, ) by>m( ±, m )> m( ) Signal forming the SFOS lepton pair closest to the mass. )> m( ) ±Z-boson OS m m( Wh経由, ) > m(, WZ経由 ± Wino-like, bino-like Selection! mass degenerate ` SRnoZa SRnoZb SRnoZc SRZa SRZb -lepton analysis based on ± reconstructing msfos [GeV] <6 6 8.p <8. or >. hadronically 8.. 8. W decaying miss ± taus. ET± [GeV] ± >5 >75 >75 75 75 OS mt -n Assume % branching of m T[GeV] via W and > < > signal regions defined rd [GeV] based > > >3on mt, with and > > T 3 via 5 GeV SM-like lightestphiggs. a b-jet veto. without SR veto SRnoZc SRnoZc h p For on-shell Higgs: m(, ) > 5 GeV b Sensitivity across parameter space achieved with signal regio Table :isd b one which above GeV, where the lepton entering mt calculation the Sarahthe Williams (CambridgeisUniversity) 5 GeV SM-like light Higgsleptons has highest BR for h (e,µ), Z-veto a same-flavour op SFOS lepton pair with/without with invariant massaclosest to theon Z-boson mass. The mt require m(l, ) >m( ±, Background )> m( ) 5 SM determin! bb to suppress background WZ events, events with W decays are char and from mmisst used to assuppress SM background 4年9月7日水曜日 Searched for mt < mw. In SRZc, the ET requirement is raisedtwo to tobackgrounds further suppress th typesgev of SM are consid identified jets (the contribution of real tau There is no requirement the number of PASCOS non-b-jets in any signal region. Table Sarah Williams (Cambridge University) 3 events with one charged leptonon (e,µ), missing transverse
Smearing - efficiency ATL-PHYS-PUB 3-4 TruthToRecoFunction pt, ηefficiency resolution parametrize Elections Truth electron Loose efficiency : ɛ(p T ) =.97.3 exp ( p T 5 ), Truth electron Tight efficiency : ɛ(p T ) =.85.9 exp ( p T ), Muons ε =.97 @ pt > 7GeV, η <.5 Jets ε =. @ pt > 5GeV, η <.5
Smearing - resolution ATL-PHYS-PUB 3-4 Elections σ(gev) =.3. E(GeV). E(GeV) for η <.4, σ(gev) =.3.5 E(GeV).5 E(GeV) for.4 < η <.47. Muons σ ID = p T σ MS = p T σ CB = a + (a p T ), ( ) b + b + (b p T ), p T σ ID σ MS σ ID + σ MS a a b b b η <.5.67.37.4.676. η >.5.3.387..388.6 Jets σ pt p T = N p T + S p T + C N = a(η) + b(η)µ pileup effect Eta a b S C.8 3..4.74.5.8. 3..3.8.5..8 3.3.3.54.5.8 3.6.8.6.83.5 3
* var: 67 cat: cut: optnj: 再構成したcosθ W θ*w の再構成精度 7 6 5 cos ) - cos (truth var:(reco.θ 77 cat:*wcut: optnj: θ*w) 4 SM WZ --- χχ (,5) 8 --- χχ (3,) 8 8 3 - -.8 -.6 -.4 -...4.6.8 L=3fb- 6 4 BGがよく組めてることが肝心 8 6 4 signalの分布は元々ほとんどflat なのでどんだけsmearされても怖くない - 4年9月7日水曜日 -.8 -.6 -.4 -...4.6.8 4
Yield SM WZ L = Y ibins µ n i i n i! e µ i e ( b ) b αb --- χχ (, ) 4 Expected Signal+BG L=3fb - µ i = s S exp i + b B exp i αs Binned Likelihood Fit! Expected Signal+BG Fit (σb: ±3%) SR SR SR SR3 - bin (shape uncertainty): a - : 3% Fit (αs) 95% Confidence level:.96σ () σ (αs) 5
- L=3fb - MC (Mχ ±, Mχ ) ~ (7 GeV, 6 GeV) 95% CL limit (L=3 (L=3fb - ) ) (GeV) m ( 8 7 6 5 4 s=4tev - ) m > m m = m m + m Z = m Discovery 3σ sensitivity reach (L (3) = 3 (L=3fb - ) ) (GeV) m ( 8 7 6 5 4 s=4tev m > m m - ) = m + m Z m = m 3 my analysis 3 my analysis Run 95%CL@.3fb - Run 95%CL@.3fb - 3 4 5 6 7 8 9 m ( ± ) (GeV) 3 4 5 6 7 8 9 m ( ± ) (GeV) 6