1 / 8

Top A FB from Heavy New Physics Model Independent Lessons

Top A FB from Heavy New Physics Model 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 ,

quincy-landry
Download Presentation

Top A FB from Heavy New Physics Model Independent Lessons

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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?

More Related