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Top A FB from Heavy New Physics Model Independent Lessons

Explore the implications of model-independent lessons derived from the study of top quark asymmetry, focusing on heavy new physics models. Analyzing the deviations observed in AFB measurements from the Standard Model and the significance of O(1) effects in tt production, this study delves into the potential impact of non-standard interactions on top quark properties. Investigate the perturbative sense of NP couplings with strong interactions and the interplay with SM gluon production. Discover the relevance of effective operators and the implications for LHC observables, offering valuable insights for the quest of understanding heavy new physics models.

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Top A FB from Heavy New Physics Model Independent Lessons

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  1. Top AFBfromHeavy New PhysicsModel Independent Lessons Cédric Delaunay Weizmann Institute of Science Israel Phys.Lett.B702:364-369,2011 & JHEP 1108:031,2011 in collaboration w/ the Weizmann dreamteam: K. Blum, O. Gedalia, Y. Hochberg, S.J. Lee, Y. Nir, G. Perez & Y. Soreq August 31, 2011 | CERN

  2. Tevatron Data Basic fact:o(5) AFBmeasurementsdifferfrom SM: CDF: l+j & ll (incl+diff)| DØ: l+j (incl) & lep AFB whileXsec(incl+diff)is consistent withit. Kamenik et al. ‘11 O(1) effects, more pronounced @higherenergies New Physics ?? Ahrens et al. ‘10 Westhoff ‘11

  3. New PhysicsInterpretation • Let’s assume experiments are correct itis new physics • zerothorderlessonsfromO(1) NP effects in tt production: • strong production • tree-level(i.e. LO QCD) • mustinterfere w/ SM source if not, >2σ tension with data! • 2 paths to explain data: • light NP | ΛNP < TeV • heavy NP | ΛNP > few TeV (w/ stronger NP couplings) • this talk focuses on the latter AFB & Xsec fit (mtt>450GeV) Grinstein et al. ‘11

  4. Blum et al. ’11 Delaunay et al. ‘11 Heavy NP & EFT approach • effective operators relevant to qq tt transitions @highmtt above 450GeV, q≈u(dd/uu≈20%, whichweneglecthere) non SM-like NLO corrections alsoneglected(thisispQCDafter all) o(Λ2) : o(Λ4) : none (if NP couplings to qq/tt are strong) (in the perturbativesense, seelater) interfere w/ SM gluon production don’tinterfere w/ SM

  5. Heavy NP & EFT approach Blum et al. ’11 • o(mtt2/Λ2) effects:  SM • CDF AFB(mtt>450) ≈ 50%cA8 ≈ 2.4/TeV2 So far, welearnthat: • sinceΛ>1-2TeV, NP couplings are sizable, at least o(1) • fromperturbativityΛ<4π/√2.4≈8 TeV • Implications for other observables | 1sthintsfrom(OA8)2 • boosted top excess @CDF (Alon et al ’10 | seealsoGilad’s talk) AFBimpliesNP/SM ~ 2 ≈ observed - 1σ • enhancement of the tt-tail @LHC again, AFBimpliesNP/SM ~ 5@mtt= 1.5TeV (cV8 = 0, sothatXsecis ok) thereis a regionwhere EFT expansion makessense.

  6. Heavy NP & EFT approach Delaunay et al. ‘11 • o(mtt4/Λ4) effects: all (4f-operators)2 kinematicaldiff. ~ 4mtop2/mtt2≈ o(20/50%) for mtt=800/450GeV , but furthersuppressed (if not vanishing) whenAFBismaximazed. • If neglected, a simple polar basis for non-interferingopsemerges withinwhich NP/SM Xsec ratio & top AFB read: • Now, one canstart do physics&drawgenericlessons about heavy NP as a explanation of AFB anomalies. a,b,d,e,α,β = kinematical #’s

  7. Model Independent Lessonsfrom EFT Delaunay et al. ‘11 AFB>450~50% & NP/SM diff-Xsec < 1σ welearnthat: [c]=[R]=TeV-2 • cA8 > 0.3/TeV2 (recall NP must interfere) • R < 3.1/TeV2 • single chiral operatorcan’treproduceAFB (θ=0) Implications for LHC tt-tail smoking gun: NP/SM > 2 @1.5TeV (LHC verdict availablesoon…?)

  8. Last words • implication for boosted tops @CDF: AFB w/in 1σimpliesNP/SM>50% • dijets production @LHC? • fromqqttit self via loop: ok! • @tree-levelfromqqqq: ok, provided NP couplingsgqq/gtt<1/5 ! • any questions?

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