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Status of LC physics study group in Japan (I)

Status of LC physics study group in Japan (I). Nobuchika Okada (KEK). LC Physics Study Meeting March 6 (Sun), 2005. Japanese LC Physics Study Group http://www-jlc.kek.jp/subg/physics/. a mixture of experimentalists and theorists mainly working in Japan. Subgroups

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Status of LC physics study group in Japan (I)

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  1. Status of LC physics study group in Japan (I) Nobuchika Okada (KEK) LC Physics Study Meeting March 6 (Sun), 2005

  2. Japanese LC Physics Study Group http://www-jlc.kek.jp/subg/physics/ a mixture of experimentalists and theorists mainly working in Japan. Subgroups Higgs, New Physics, Top, Gamma-Gamma (ee–option), Luminosity

  3. Higgs subgroup activities and related works Higgs physics at LC Higgs boson  EW symmetry breaking mass generation mechanism Measurement of Higgs boson mass and self coupling  structure of EW symmetry breaking New physics if

  4. etc.. etc.. Studies on Higgs self coupling measurement by Y. Yasui and S. Yamashita • Priority ⇒HiggsPhysics at TeV LC • Higgs self coupling⇒We started (from 2002) • Top Yukawa • Heavy Higgs, etc.

  5. @LCWS '02 Jeju Korea Assumption No bkg effects 100% signal efficiency dominant for ECM > 1TeV by Yasui et.al. LCWS’04 Paris France 　Quick Simulation (includesbkg.) study!!

  6. Simulation Study Ecm = 1 TeVmain mode  W-fusion Higgs mass = 120 GeV SM decay Br ISR/BSR included Signal & bkg event generatorLCGrace (BASES+SPRING) Signal MC: X + hh/SM from 0.0 to 2.0 with 0.2 step Smearing simulation at parton levelJet energy resolution ~ 30%/√E (GeV) (detector R&D target value) ννhh quick analyses only for hh decaying to 4b Br(hh4b) ~ 47 % for 120 GeV SM Higgs Signal characteristics Large missing energy, missing Pt Only 4 b jets M1 jj ~ Mh M2 jj ~ Mh No isolated lepton

  7. ννbbbb(~ ννZZ, ννZγ*) ννbbh (~ ννZh) Signal and Background processes By LCGrace Main bkg processes 4b + missing Signal (for SM)

  8. 1. Likelihood selection bkg further reduction 2. Separate Zhh & fusion differentdependence (positive/negative interferences) 3. Combine with Zhh analyses for s-channel process 4. Check hh invariant mass 5. hhhmeasurements dep. of cross-section Zhh eehh /SM Reconstructed ‘Higgs’ mass ννhhAnalysis Flow ννbbbb = ννbbh =SM L = 1 ab-1

  9. ννhh selection ννhh channel L = 1 ab-1 ννbbbb = ‘fusion’ ννhh counts counts =SM ννbbh ‘Zhh’ Likelihood Missing mass [GeV] Separate Zhh & fusion (~ OPAL Higgs scheme)

  10. ‘Zhh-channel’ ‘fusion-channel’ = =2 SM Zhh counts counts ννhh =SM =SM hh invariant mass [GeV] hh invariant mass [GeV] (= visible mass) HH invariant mass distributions

  11. @1TeV Ilumi=1 ab-1 Pol beam= -80% 95%CL upper bound Measured /SM Mh=120 GeV (SM Higgs Br) Mh=120 GeV Use only hh4b 67%CL range (Br(hh4b)~47%) Eff.(4b) 80% 95%CL lower bound True/SM hhhMeasurement sensitivity By Yamashita et.al. LCWS 2004 Precise studyRadiative corrections are also important!! Systematic study of the RC for Higgs physics at LC with GRACE

  12. Higgs coupling constants as a probe of new physics S. Kanemura, S. Kiyoura, Y. Okada, E. Senaha, C.-P.Yuan, PLB558(2003)157. S. Kanemura, Y. Okada, E. Senaha, C.-P. Yuan, PRD70(2004)115002.

  13. Higgs coupling constants as a probe of new physics Z t h Top loop effects (SM) Z h t h h

  14. Z Φ h Z h Φ h h S. Kanemura, S. Kiyoura, Y. Okada, E. Senaha, C.-P Yuan

  15. S. Kanemura, Y.Okada, E. Senaha, C.-P. Yuan Allowed region of the deviation from the SM of the hZZ and hhh coupling (M = 0 case ) δ= 0corresponds to the decoupling limit； sin(β－α)　＝１ hZZ ⇒deviation mainly comes from the tree-level mixing effect (radiative correction －1%) hhh ⇒the tree-level mixing effectO(10%) radiative correction O(+100)% due to the non-decoupling loop effect

  16. Connection between collider physics and cosmology Electroweak baryogenesis and quantum corrections to the triple Higgs boson coupling S. Kanemura, Y. Okada, E. Senaha, PLB606(2005)361.

  17. Electroweak Baryogenesis and quantum corrections to the triple Higgs boson couplings By the non-decoupling loop effect of extra Higgs bosons, the renormalized hhh coupling (h: SM like Higgs boson) in the 2HDM can differ from the SM prediction by O(100%) Large deviation in hhh due to the non-decoupling effect corresponds to the successful scenario of electroweak baryogenesis Baryogenesis : C, CP violation 2HDM Out of equilibrium 1st order PT S. Kanemura, Y. Okada, E.Senaha Spharelon condition Cubic term can be sufficiently large due to non-decoupling effect of extra Higgs boson loop Sphaleron condition

  18. Search for the lepton flavor violating Yukawa interaction via the Higgs boson decay S. Kanemura, K. Matsuda, T. Ota, T. Shindou, E. Takasugi, K. Tsumura, PLB599(2004)83, S. Kanemura, T. Ota, K. Tsumura, work in progress.

  19. S. Kanemura, K. Matsuda, T. Ota, T. Shindou, E. Takasugi, K. Tsumura Search for LFV via the Higgs decay LFV Higgs coupling may be measured at LC Mh=120GeV, L=1ab^-1

  20. Extension to the general 2HDM S. Kanemura, T. Ota, K. Tsumura Similar to the MSSM, but no SUSY relation among Higgs parameters Constraint on parameters: LEP precision data Perturbative unitarity Vacuum stability For the low tanβ region, no constraint on h →μτfrom tau rare decayresults Measurement of h→τμ at LC can give strong constraint on κ32 esp for low tanβ

  21. Search for Lepton Flavor Violating Deep Inelastic Scattering Processes Possibility of a fixed target experiment at LC S. Kanemura, Y. Kuno, M. Kuze, T. Ota, PLB607 (2005) 165.

  22. Alternative process for search of the Higgs LFV coupling. • At future ν factories (μ colliders) , 10^20 muons of energy 50 GeV (100-500GeV) can be available. DISμＮ→τＸprocess • At a LC (Ecm=500GeV L=10^34/cm^2/s) 10^22 of 250GeV electrons available. DIS process eＮ→τＸprocess A fixed target experiment option of LC

  23. Cross section in SUSY model • Each sub-process e q (μq) →τq is proportional to the down-type quark masses. • For the energy > 60 GeV, the total cross section is enhanced due to the b-quark sub-process E ＝50 GeV 10^(-5)fb 100 GeV10^(-4)fb 250 GeV10^(-3)fb CTEQ6L

  24. Phenomenology of CP violating Higgs sector in the MSSM A. Akeroyd, S. Kanemura, Y. Okada, E. Senaha, hep-ph/0409318

  25. A. Akeroyd, S. Kanemura, Y. Okada, E. Senaha

  26. SUSY loop contributions to the W pair production K. Hagiwara, S. Kanemura, M. Klasen, Y. Umeda, PRD68(2004)1103011. S. Alam, K. Hagiwara, S. Kanemura, Y. Umeda, R. Szalapski, PRD62(2000)095011; NPB541(1999)50.

  27. SUSY loop contributions to K. Hagiwara, S. Kanemura, Y. Umeda • Calculation tested by the • BRS sum rules • Decoupling property • The typical size of the contributions to M(00) • a few times 0.1 % for sfermion effects • O(1%) for chargino/neutralino effects • CP phase effect in the chargino/neutralino sector • At most 0.1% in M(0+) : Goldstone boson Gounaris et al The one-loop form factors are tested except for overall renormalization

  28. Sfermion effects First 2 generation squark effect Stop-sbottom loop effect

  29. Chargino/neutralino effects CP phase effect CP odd form factors F4, F6, F7

  30. New Physics subgroup activities and related works Collider signal of New Physcs: MSSM, Large extra-dimensions etc. 1) Studies on MSSM Mass and cross-section measurements of chargino productionat LC by Y. Kato, K. Fujii, T. Kamon, V. Khotilovich, M. M. Nojiri to be published in PLB (hep-ph/0411249) Chargino pair production process is one of the key for determination of supersymmetric parameters at LC If large tan beta  Event:

  31. 2) Collider signal of large extra dimensions Large extra-dimension (ADD) scenario (Arkani-Hamed-Dimopoulos-Dvali, ’98) Phenomenology of graviton Kaluza-Klein modes Detection of Extra-dimension @ LC through KK graviton mediated processes KK graviton mediated process

  32. Important points: I: total cross section  new physics evidence deviation from the SM collider energy LC < LHC II: angular dependence of cross section  effects due to spin 2 particle exchange precise measurements of angular dependence LC > LHC

  33. Example: N. Delerue, K. Fujii & N. Okada PRD 70, 091701 (2004) process KK graviton exchange is dominant SM background free  very interesting if this cross section is large enough Comparable to

  34. Characteristic angular dependence of cross section  Reflects spin 2 nature of KK graviton

  35. Invariant mass distributions

  36. Invariant mass distributions

  37. Number of remaining evens per 700 Higgs Pair events @ 1TeV LC integrated luminosity 500 Essentially No SM backgrounds!

  38. Reconstruction of Angular Distribution (after selection) integrated luminosity 500 Future plan Next example: is now work in progress….

  39. subgroup activities and related works γ • Higgs • SM Higgs/Light Higgs t, b, W, ‥‥ h γ Study method is already established. : ~2% accuracy for mh = 120–140 GeV • Heavy Neutral Higgs in SUSY, 2HDM, etc. Mass reach is heavier than e+e- pair production single production

  40. Heavy Neutral Higgs in SUSY, 2HDM, etc. (1) Production: A-H-continuum intreference A, H t t － － t t Comparable around the resonance Large Interference effects ! Asakawa-Kamoshita-Sugamoto-Watanabe Eur.Phys.J.C14:335(2000)

  41. Asakawa-Hagiwara Eur.Phys.J.C31.351(2003) (2) Phase of γγΦ: • magnitude of the vertex ⇔Γ(φ→γγ) • phase of the vertex ⇔Observables including interference effects • They are sensitive to existence of new charged particles. events /GeV for Lee=3fb-1 bγ: γγφ vertex σ λ σ bγ λ λ λ σ σ

  42. Large Extra-dimensions Collaboration is being groped. • Tools • GRACE/SUSY/1LOOP-CAIN Automatic calculation up to 1-loop level in SM&MSSM with REALISTIC photon luminosity simulations Basically, has been developed. Other activities  Yasui-san’s talk

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