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New Physics Search through gg → t t → l X / b X

7th International Symposium on Radiative Corrections. New Physics Search through gg → t t → l X / b X. 7/Oct./2005@Shonan Village. Kazumasa OHKUMA ( Fukui Tech. ). Based on. hep-ph/0508183. PLB593 (2004) 189 & NPB689 (2004) 108. In collaboration with. Z. Hioki （ Tokushima Univ. ）.

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New Physics Search through gg → t t → l X / b X

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  1. 7th International Symposium on Radiative Corrections New Physics Search through gg → t t→ l X / b X 7/Oct./2005@Shonan Village Kazumasa OHKUMA(Fukui Tech.) Based on hep-ph/0508183 PLB593 (2004) 189&NPB689 (2004) 108 In collaboration with Z. Hioki（TokushimaUniv.） B.Grzadkowski(Warsaw Univ.) , J.Wudka（UC Riverside)

  2. Plan of talk I. Introduction II. Framework III. Optimal-Observable Analysis IV. Summary

  3. 7/Oct./2005 Shonan Village Page-1 7th International Symposium on Radiative Corrections I. Introduction ★StandardModel iscomposed by Electro-weak theory and Quantum chromodynamics Highly Successful Model But!! There are some unsolved problems • Many parameters (Couplings, CKM, ‥‥) • Origin of masses • Hierarchy New Physics beyond Standard Model

  4. How to search for the signal of new physics? 7/Oct./2005 Shonan Village Page-2 7th International Symposium on Radiative Corrections Top quark physics. One of answers: Why? Ans. There are someadvantageous properties; (1) Heaviest particle observed to date ! ! (i) Sensitive to SSB Higgs (ii) Decay as a free quark ! τ<<10-23[s] Clear information about top quark (2) On top quark sector, CP isnegligible in SM ! ! Large CP indicates new physics contribution.

  5. In order to study non-standard effect , we focus on Only CP-even state at ee collider 7/Oct./2005 Shonan Village Page-3 7th International Symposium on Radiative Corrections at Photon Collider • Interesting option of ILC. • Initial CP parity is controllable!! • Couple to CP-odd scalar particles We estimate Statistical Significance of non-Standard Couplings and probe Optimal Beam Polarizations for New Physics Search

  6. ★ Effective Lagrangian approach Model Independent Analysis : Energy scale of new physics 7/Oct./2005 Shonan Village Page-4 7th International Symposium on Radiative Corrections II.Framework Complementary relation ModelDependentAnalysis Assumption • New fields are not in existence under L scale. • New heavy particles are decoupled. • SM Lagrangian is modified by quantum effectof new physics. : SU(3) X SU(2) X U(1) invariant Dim.6 operators : non-standard couplings W.Buchmuller and D.Wyler, NPB268(1986)621

  7. Top Quark Production 7/Oct./2005 Shonan Village Page-5 7th International Symposium on Radiative Corrections Effective Operators for γγ→ tt • ｔｔginteraction (Top EDM) • ｔｔgginteraction (Contact Interaction) We found relations between EDM operators and Contact interaction operators.

  8. Relations of Operators 7/Oct./2005 Shonan Village Page-6 7th International Symposium on Radiative Corrections Bianchi identities and SM classical motion of equations for quark and vector bosons lead us to

  9. × × × × × × × × × × × : No contribution Need not to consider Contact Interaction.

  10. Effective Operators for gg→(H)→tt 7/Oct./2005 Shonan Village Page-7 7th International Symposium on Radiative Corrections • ggHinteraction (Higgs property) • Top Decay Effective Operators for t →ｂW • ｔｂW interaction

  11. 7/Oct./2005 Shonan Village Page-8 7th International Symposium on Radiative Corrections Feynman rules for on-shell photos ★ Top Electric Dipole Momentinteraction : ag (1) CP-conserving ttgvertex (2) CP-violating ttgvertex ★ HiggsExchange interaction : ah (1) CP-conserving ggH vertex (2)CP-violating ggH vertex

  12. 7/Oct./2005 Shonan Village Page-9 7th International Symposium on Radiative Corrections ★ Decay Vertex

  13. 7/Oct./2005 Shonan Village Page-10 7th International Symposium on Radiative Corrections Feynman Diagrams for gg →　ｔｔ S.Y.Choi and Hagiwara PLB359(1995)369, P.Poulos and S.D.Rindani PRD56(1997)6835, etc. B.Grzadkowski and J.F.Gunion, PLB294(1992)316, G.J.Gounaris and G.P.Tsirigoti,PRD56(1997)3030, E.Asakawa, J.Kamoshita, A.Sugamoto and I.Watanabe,EPJC14(2000)335, E.Asakawa, S.Y.Choi,K.Hagiwara and J.S.Lee, PRD62(2000)115005, R.M.Godbole, S.D.Rindani and R.K.Shigh PRD67(2003)095009, etc. In actual experiment, their mixed signals will be observed !! All possible non-standard interactions are taken into account.

  14. How to estimate these precision ? 7/Oct./2005 Shonan Village Page-11 7th International Symposium on Radiative Corrections III.OptimalObservable Analysis What is Optimal Observable Analysis ? Method for estimating the precision of determination of relevant non-standard couplings. J. F. Gunion, et.al, PRL77 (1996) 5172 Suppose following distribution: Cross section : final-state phase space : known functions ← Calculable : model-independent coefficients

  15. 7/Oct./2005 Shonan Village Page-12 7th International Symposium on Radiative Corrections Extract Ciusing appropriate weighting function Extract In general, different choice for the are possible. There is a unique choice which minimizes the resultant statistical uncertainty: DCi. Such function is given by

  16. 7/Oct./2005 Shonan Village Page-13 7th International Symposium on Radiative Corrections Inverse matrix of Mij : Calculable Statistical uncertainty of Ci is given by : Event number : Total cross section Apply to analysis of final-lepton’s energy and angular distribution for .

  17. Application Calculable 7/Oct./2005 Shonan Village Page-14 7th International Symposium on Radiative Corrections e.g. Final-lepton’s energy and angular distribution EDM Higgs Decay

  18. 7/Oct./2005 Shonan Village Page-15 7th International Symposium on Radiative Corrections Matrix Element Mij Inverse where I,J=1,‥,6 correspond to SM, g１,g２, h1, h2 and d, respectively. EX.

  19. Parameters of Photon collider : Degree of linear polarization of initial laser with azimuthal angle : Degree of circular polarization of initial laser 7/Oct./2005 Shonan Village Page-16 7th International Symposium on Radiative Corrections High energy colliding beams of polarized photons are generated by Compton backscattering : Initial electron longitudinal polarization

  20. Probing optimal photon beam polarizations Search for the combinations that make minimal, varying polarization parameters as Note 7/Oct./2005 Shonan Village Page-17 7th International Symposium on Radiative Corrections Estimate the uncertainty of couplings

  21. Assumption Some non-standard couplings Ci have been measured in other processes e.g. 7/Oct./2005 Shonan Village Page-18 7th International Symposium on Radiative Corrections Unfortunately ! Our results for Xijare very unstable even a tiny fluctuation ofMij changes Xij significantly ! All the couplings cannot be determined at the same time from only . Refrain from determining all the couplings at once.

  22. 3 and 2 parameters analysis give stable solutions within 10% ambiguity 5 and 4 parameters analyses lead to unstable solutions. 7/Oct./2005 Shonan Village Page-19 7th International Symposium on Radiative Corrections Result Under the conditions: , , 2 parameter case : 68 combinations are OK final lepton 39 final bottom 29 3 parameter case : 3 combinations are OK final lepton 1 final bottom 2 Some results are presented hereafter.

  23. Not so small ! 7/Oct./2005 Shonan Village Page-20 7th International Symposium on Radiative Corrections Results (3 parameter analysis) (2 of 3) Bottom-quark detection Charged-lepton detection with with : detection efficiency

  24. for each pair of and 7/Oct./2005 Shonan Village Page-21 7th International Symposium on Radiative Corrections Results (2 parameter analysis) There are 68 stable solutions. However All the stable solutions do not give us good statistical precisions. Two statistical uncertainties ( , ) satisfy is minimal

  25. 7/Oct./2005 Shonan Village Page-22 7th International Symposium on Radiative Corrections Results (2 parameter analysis) • mH=300 GeV • Final lepton detection

  26. 7/Oct./2005 Shonan Village Page-23 7th International Symposium on Radiative Corrections Results (2 parameter analysis) • mH=300 GeV • Final bottom quark detection

  27. Note There are no combinations which make ag2 small (ag2 < 0.1). 7/Oct./2005 Shonan Village Page-24 7th International Symposium on Radiative Corrections Results (2 parameter analysis) • Independent of Higgs mass • Final lepton detection

  28. 7/Oct./2005 Shonan Village Page-25 7th International Symposium on Radiative Corrections IV. Summary To study non-standard Effect in top quark production, we focus on . • Model independent analysis were performed • usingeffective low-energy Lagrangian. • Statistical uncertainties were estimated • CP conserving and violating ttg coupling :ag1,ag2 • CP conserving and violating ggH coupling:ah1,ah2 • anomalous tbWcoupling :ad • using Optimal Observable method. Probe Optimal beam polarizations for New physics search

  29. 7/Oct./2005 Shonan Village Page-26 7th International Symposium on Radiative Corrections • Adjusting beam polarization gives us • good statistical precisions: • in two parameter analysis • all non-standard couplings （except for ag2） • could be determined with accuracy better • than 0.1 with a integrated luminosity of • 500 fb-1. • the statistical uncertainty of ag2 is still • large in this analysis. It is useful to probe the proprieties of Higgs boson couplings. We look for anther processes to determine ag2.

  30. Back up

  31. ee collider • It is possible to measure ttg couplingat both colliders. • Within the framework of the effective Lagrangian, we can estimate Dag . 7/Oct./2005 Shonan Village Appendix 7th International Symposium on Radiative Corrections Comparing ee and gg colliders • Top quark productions gg collider

  32. Note! In the eettl / b X , ag2 could not be measured. 7/Oct./2005 Shonan Village Appendix 7th International Symposium on Radiative Corrections In ggttl /bX , ag2 could be measured though it’s not to be measured precisely. B.Grazkowski and Z. Hioki, NP B484 (1997) 17, NP B585 (2000) 3 L. Brzezinski, Grzadkowski and Z. Hioki, Int. J. Mod. Phys. A14 (1999) 1261

  33. Comparisonofag1measurementin ee and gg colliders • eettlX ee colliders will give us slightly good precision. • ggttlX 7/Oct./2005 Shonan Village Appendix 7th International Symposium on Radiative Corrections 1 parameter Optimal Observable analysis

  34. Comparing ee and gg colliders • ee collider ( ee ttl / bX ) • It seems to be slightly favored to measure ag1. • ag2 could not measure in the process. • gg collider ( ggttl / bX ) • ag2 could be measured in the process. (precision is not good) • It seems to be very useful for testing the Higgs coupling. Looking for the processes or observable that make statistical sensitivity small for the measuring ag2 is important !

  35. Circular polarization Asymmetry (-) (-) 7/Oct./2005 Shonan Village Appendix 7th International Symposium on Radiative Corrections

  36. Linear polarization Asymmetry 7/Oct./2005 Shonan Village Appendix 7th International Symposium on Radiative Corrections

  37. 7/Oct./2005 Shonan Village Appendix 7th International Symposium on Radiative Corrections Results (2 parameter analysis) • mH=300 GeV • Final bottom quark detection

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