Higgs Sector in New Physics and its Collider Phenomenology

Transcription

1 Higgs Sector in New Physics and its Collider Phenomenology Shinya KANEMURA University of TOYAMA 7-8. Dec. 2008, ICRR Theory Meeting

2 Plan of This Talk Electroweak Symmetry Breaking SM Higgs property Search at LHC New Physics and its Higgs Secter Motivation Physics of Extended Higgs models A extended Higgs model for neutirno mass, DM and baryon asymmetry Summary

3 Electroweak symmetry breaking in the SM Higgs sector is unknown EWSB: SU(2)I U(1)Y U(1)EM A scalar iso-doublet Higgs potential of SM m H : Last unknown parameter of the SM Origin of Mass Light Higgs Weak coupling Heavy Higgs Strong coupling v

4 Higgs Coupling Mass-Coupling Universarity in the SM Origin of all masses is VEV Mass & Higgs Coupling Not measured SM Higgs can be tested by using this relation In other Higgs models, this relation does not hold Precise measurement of mass and coupling is necessary

5 Theoretical Constraint on m H in SM Requirement for the stability of the theory below a cutoff scale Λ RGE

6 Constraint on m H from current data Search at LEP 114 < mh < 144 GeV (95% CL) 185 GeV (95% CL) [incl. direct search] Direct search Indirect bound via the oblique correction In the SM, a light Higgs (< 200 GeV) is favored from both theory (triviality) and the data

7 Light Higgs? (Weakly interacted?) In SM, LEP data and triviality bounds (with high L) prefer a light Higgs boson If L is low, a heavier Higgs boson can be allowed in BSM! Effective Theory (Λ~O(TeV)) Dr=aT mh=100 NP contribution Two Higgs doublets Heavy (SM-like) Higgs boson is possible in BSM

8 Decay branching ratios Low mass < 140GeV Yukawa coupling bb, tt, cc gg (top-loop) gg (top-loop) Higher mass Almost WW(*), ZZ(*) Goldplated mode Large S/N (tt never dominant)

9 Production of the SM Gluon Fusion H gg ( GeV) H ZZ llll ( GeV) H WW ( ) Vector Boson Fusion (VBF) H tt ( GeV) H WW ( GeV) H gg ( GeV) H bb ( GeV) Y b g HWW W association H WW ( GeV) g HWW Production cross section Top association H bb ( GeV) Yt H tt ( GeV) Yt H WW ( GeV) Yt

10 100 < m H < 150 GeV Slide by R. Tanaka

11 H t t from VBF Forward jet Tagging B-jet veto Central jet veto Co-linear approx. for tau s Forward two jets Small hadronic activity except for jets from produced Higgs bosons

12 Discovery Potential

13 Coupling measurement To be measured Put a mild theoretical assumption Duhrssen, Heinemeyer, Logan, Rainwater, Weiglein, Zeppenfeld hep-ph/ Combined with measurement of H->VV in WBF, this gives an upper bound on the total width Relative precision of coupling-square

14 Self coupling measurement

15 Precision Measurement for Higgs Mass and Couplings at LHC LHC with L=300fb -1 Dm H ~ 0.1 % Coupling ~ 10-30% m H =120GeV with mild asuumptions In this expected accuracies, the mass-coupling relation can be tested at LHC

16 Precision Measurement for Higgs Mass and Couplings at LHC LHC with L=300fb -1 Dm H ~ 0.1 % Coupling ~ 10-30% LHC 300 m H =120GeV with mild assumptions In these expected accuracies, the mass-coupling relation can be tested at LHC ILC International Linear Collider (ILC) will make it much more accurate!! Charm Yukawa, Self-coupling

17 Possibility of extended Higgs sector Higgs sector is unknown Possibility of various Higgs models can be considered Some new physics models predict extended Higgs sectors Naturalness SUSY (MSSM, NMSSM, ), DSB, Little Higgs, Neutrino masses (Zee-type model) EW baryogenesis (1 st OPT, extra CP phases) CDM (Dark scalar) Extended Higgs sector New Physics Scenario

18 Extended Higgs Sector Primary constraints from Data: EW ρ parameter FCNC r = 1 (tree) Ti ( Ti 1) Yi vi ci m W i Z cos W 2 i i i r = m Y v Possible way of extension 1.Multi-doublets (D) +singlets(s) FCNC control by (Softly broken) Discrete Symmetry 2.D + triplets(t) a) Small VEV for T: ρ~1 b) Custodial Symmetry: ρ~1 (D+T 0 +T 2 : Georgi-Machasek Model) T Y v i i i c i : SU(2) L isospin : hypercharge : v.e.v. :1 for complex representation 1/2 for real representation

19 2HDM Simpletst extension with r = 1 and no FCNC at tree Mass eigenstates and mixing angles Mass eigenstates

20 FCNC suppression 1-Higgs doublet GIM, qq(v+h) no FCNC at tree 2-Higgs doublets Higgs eigenstates == Mass eigenstates FCNC appear! Softly-broken Z 2 symmetry (Z 2 ) ~ Glashow -Weinberg Each quark or lepton couples to only 1 of the 2 Higgs doublets No FCNC at tree 4 Petterns of Yukawa coupling Type Y Type X

21 b sγ The NLO calculation and the data NLO by Ciuchini et al 98 Boltmati/Greub Chetyrkin/Misiak/Munz Kagan/Neubert NNLO by Misial et al Becher, Neubert 2006 TYPE Y Central value of the Data TYPE X M. Aoki, S.K., K. Tsumura, K. Yagyu, in preparation Type I, Type X: free from the b s g result even for m H+ =100GeV

22 a = cot 2 b (Type I, Type X) 1 (Type II)

23 2HDM (Type2) MSSM Higgs sector λ=o(g 2 ) Mass of the lightest Higgs boson SUSY Mass formula

24 MSSM (2HDM type2) Higgs couplings Higgs mixing SM 2HDM type II (MSSM) Down quarks, leptons tanb Decoupling Limit m A >> m W Up quarks, leptons 1 cotb

25 MSSM Higgs at LHC Discovery SM like Higgs Extra Higgs bosons (tanb enhance) H tanb enhancement of Yukawa coupling Is used to extend Discovery regions Only SM Higgs

26 Phenomena of Beyond-SM Neutrino Oscillation BSM! Dm sol 2 ~ ev 2, Dm atm 2 ~ ev 2 Dark Matter W DM h 2 ~ 0.11 WIMP : Baryon Asymmetry of the Universe n B /s ~ BSM! Sakharov s condition Electroweak Baryogenesis SM is excluded by LEP B violation C,CP violation Non-equiliblium BSM!

27 Scenario with super high scales Ex) Supersymmetry Stabilize the model up to Planck Scale Grand Unification, connection to superstring, large mass scales can be considered Neutino Mass Baryon Asymmetry R-parity WIMP Dark Matter Seesaw? Leptogenesis, AD etc,? LSP? There is an alternative scenario due to TeV scale physics w/o high scales (extended Higgs sectors)

28 An extended Higgs Model for Neutrio Mass, Dark Matter and Baryon Assymmetry Possibility to simultaneously explain Mayumi Aoki, SK, Osamu Seto arxiv: Neutrino Mass Dark Matter Baryon Asymmetry of the Universe by the TeV physics without introducing large scales. A renormalizable theory at TeV scales All mass scales in the Lagrangian is TeV or below No dim-5 or higher order operator in the Lagrangian Predictable and testable at collider experiments

29 Neutrino Mass and Higgs Neutirno Mass Term (= Effective Dim-5 operator) L eff = c ij n i n j f f <f> = v = 246GeV Mechanisms for m n ij= (c ij v 2 ) < 0.1eV Seesaw (tree level) m n ij = y i y j v 2 /M M= GeV Quantum Effects M can be scaled down by loop suppression m n ij = [1/(16p 2 )] n C ij v 2 /M M=1 TeV

30 Scenarios of radiative nnff generation Tiny n-masses come from loop effects Zee (1980, 1985) Zee-Babu, Ma, Sarker,.. Krauss-Nasri-Trodden (2002) Ma (2006),.. Merit Super heavy particles are not necessary. Tiny n masses are radiatively generated from the TeV physics by loop suppression. Zee Krauss et al Physics at TeV: Testable at collider experiments

31 The Model SM + extended Higgs + TeV-RHn Exact Z 2 Parity No neutrino Yukawa Stabilize Dark Matter Z 2 odd TeV-scale RH neutrinos: N R Extended Higgs: 2HDM + gauge singlets (h 0, S + ) 3 loop effect (N R, h 0, S +, H +, e R ) : Tiny neutrino mass Lightest Z 2 -odd particle (h 0 ) : DM candidate Extended Higgs [1 st Order PT, Source of CPV] : EW baryogenesis

32 The Model Z 2 (exact) : to forbid n-yukawa to stabilize DM ~ (softly-broken): to avoid FCNC Z 2 F 2 F 1 Type-X Neutrino data require a light H + (~100GeV) Type-X Yukawa Coupling (to satidfy bsg data) Different phenomenology from MSSM (Type-2) Higgs sector

33 Lagrangian Z 2 even(2hdm) + Z 2 odd(s +, h 0, N Ra ) Z 2 (exact) : to forbid tree n-yukawa and to stabilize DM (softly-broken): to avoid FCNC ~ Z 2 Z 2 even 2HDM Z 2 odd scalars Interaction RH neutrinos

34 Neutrino Mass (radiative nnff generation) Induced at 3-loop Tree level neutrino Yukawa is forbidden by exact Z 2 Universal scale of m n is determined by 3-loop function factor F Mixing structure is determined by C a ij F ~ 10 4 ev C a ee ~ k 2 tan 2 b h e h e (10-5 ) 2 ~10-6 M ee ~ 10-2 ev We can describe all the neutrino data without unnatural assumption among mass scales

35 Solution of n mass and mixing Case of 2 generation N R a Dm 2 sol ~ ev 2 Dm 2 atm ~ ev 2 sol ~ atm ~ p/4 m H+ =m H =100 GeV, m h =50GeV, m NR1 =m NR2 =3.5 TeV Set A (B): k tanb =36 (42) and U e3 =0 (0.18).

36 Thermal Relic Abundance of η 0 WMAP data (τ - ) k v (τ + ) k v The 1-loop process gg can be comparable to the bb and tt processes, when s, Y f << k. m h would be around GeV for m S = 400GeV

37 Electroweak Baryogenesis Sakharov s conditions: Baryon number violation C, and CP violation Departure from thermal equilibrium Strong 1 st Order Phase Transition = rapid sphaleron decoupling in the broken phase Effective Potential at high T EW baryogenesis in 2HDM Cohen, Kaplan, Nelson, 1991,.. Cline, Kainulainen, Vischer 1996,.. Fromme, Huber, Seniuch 2006

38 Electroweak Phase Transition Strong 1 st OPT = non-decoupling prop. m A2 =M 2 +(l 4 -l 5 )v 2 /2 m S2 =m S2 +l S v 2 m h =120GeV m H +=m H =100GeV M=100 GeV, m S =200GeV When M 2, m S2 (invariant masses) << l i v 2 (DM abundances require m S > 400GeV) f C /T C < 1 Large deviation in hhh coupling (> 20 %). Testable at ILC? SK, Okada, Senaha

39 Mass Spectrum The current data and requirement for Neutrino data DM Strong 1 st OPT LEP bounds b sg, B tn LFV (m e g), g-2, tau leptonic decay Tevatron bound (H + from the t decay) All the masses are predicted as O(100) GeV O(1) TeV Collider Exp. 1TeV 400GeV 200GeV 100GeV 50GeV h A N R S + H, H + h (DM)

40 SM-like Higgs invisible decay Physics of h h is the SM-like Higgs boson but B(h hh) = 50 (37) % for m h =48 (57) GeV Invisible decay: testable at LHC and ILC h from Halo can basically be detected at the direct DM search (CDMS, XMASS) h Nucleus (Xe, Ge) h Observing the release energy Several times 10 % of invisible decay (h hh)

41 H 0 (extra Higgs) decay Type X phenomenology F 1 only couples to Leptons F 2 only couples to Quarks Type II: bb dominant Type X: tt dominant

42 H + (extra Higgs) decay Type X phenomenology F 1 only couples to Leptons F 2 only couples to Quarks Type II & Type X: both tn dominant

43 in the SM Ratio of between 2HDM and SM tanb=3 Backgrounds About 2 times more signal in Type-X than in the SM

44 Light Higgs scenario: Production at the LHC m H+ ~ m H ~ m A ~ O(100) GeV SK, Yuan (2002) s(pp HH + ) B(H X) B(H + Y) Our model (Type X) B(H tt) ~1 pp HH + (tt)(t n) MSSM (Type II) B(H bb) ~1 pp HH + (bb)(t n) Decay modes depend on the model (Type II or X) [(mm)(t n)] m A (GeV)

45 Signal Backgrounds gw bbw tb tt Shinya KANEMURA

46 Q.-H. Cao, S.K., C.-P. Yuan 2004 Monte Carlo (parton level) Model parameters and basic cuts Shinya KANEMURA

47 Case A ma=101gev Shinya KANEMURA

48 Shinya KANEMURA

49 Transverse mass of the pion mh+ Shinya KANEMURA

50 Light Higgs scenario: Production at the ILC e + e - AH tttt (ttmm) (m A <m H +m Z ) e + e - AH e + e - H + H - tntn (tnmn) Leptonic decay dominance of H, A, H + Type-X Yukawa B(A tt), B(H tt) ~ 100 % B(A mm), B(H mm) ~ 0.3% For m H+ =m H =100 GeV with sin(b a)=1, tanb=10 m A =150GeV, E cm =500GeV, L=500fb tttt events 112 ttmm events 0 mmmm events tntn events 128 tnmn events 0 mnmn events Testable at ILC? Simulation study is necessary e + e - H + H -

51 Z 2 -odd charged scalar S + e + e - S + S - e + e - S + S - Produced in Pair 5fb for m S =400GeV at ILC 1000 Signal be hard hadrons+ large missing E m S (GeV) SK, Lin, Kasai, Okada, Yuan Ratio of G(h gg) Indirect quantum effect can be significant (hhh, hgg) h S + g g m S (GeV)

52 Summary SM Higgs is unknown LHC try to discovery SM Higgs boson mass and coupling Test SM Motivation of extended Higgs sector Hierarchy Problem NP models predict extended Higgs sectors Neutrino mass (radiative nnff generation) DM (dark scalar) Baryogenesis (EWBG: Strong 1 st OPT, CPV) Extended Higgs sector New Physics models

53 A concrete model for Summary Neutrino mass Dark Matte Baryogenesis via TeV-scale physics with Z 2 parity. F 1, F 2 (Z 2 even) h, S +, N R (Z 2 odd) Predictions in Higgs physics and DM physics Invisible decay of SM-like h Type-X Yukawa coupling Light H + (H) scenario Non-decoupling property of S + Testable at experiments M. Aoki, SK, O. Seto 2008 Distinguishable from SM, MSSM, Type-II 2HDM, etc by the experiment at LHC, ILC