Supersymmetry, Baryon Number Violation and a Hidden Higgs. David E Kaplan Johns Hopkins University

Transcription

1 Supersymmetry, Baryon Number Violation and a Hidden Higgs David E Kaplan Johns Hopkins University

2 Summary LEP looked for a SM Higgs and didn t find it. Both electroweak precision measurements and supersymmetric theories prefer a Higgs mass lighter than the LEP bound. Non-standard decays of the Higgs severely weakens current bounds and opens up SUSY parameter space New LEP(!) analyses are warranted. Higgs searches at the Tevatron and the LHC in these channels are a challenge...

3 Higgs: Direct Search Dominant bound from LEP II SM: m h > GeV b, τ e h b, τ e + Z Z

4 Decay modes of the Higgs 1 _ bb 140 GeV WW BR for SM Higgs ! +! " cc _ gg ZZ tt - ## Z# Higgs Mass (GeV)

5 SM Higgs 95% CL limit on! (a) LEP "s = GeV Observed Expected for background m H (GeV/c 2 )

6 A light Higgs is preferred by data

7 A light Higgs is preferred by data Central value at 89 GeV.

8 Corrections to the Higgs mass m 2 Z + δλ v 2 = m 2 phys = 2µ 2 + m 2 soft δλ y 4 t ln(m t /m t) grows as a log δm 2 soft yt 2 m 2 t ln(λ/m t ) grows as a power Typically need stop masses near 1 TeV

9 State of msugra GG Arkani-Hamed, Giudice, Rattazzi 06

10 SUSY: Where to Look Sweet spots in parameter space Choi, et. al. (2004), Kitano and Nomura (2005) Radical shift in view of naturalness Arkani-Hamed and Dimopoulos (2004) Mild shift in assumptions of low energy theory Dermisek and Gunion (2005), S. Chang, et.al. (2005)

11 Alternative phenomenology of the Higgs New couplings for the Higgs: b, τ e h b, τ e + Z Z

12 Alternative phenomenology of the Higgs New final states: b, τ e h b, τ e + Z Z

13 Invisible Higgs LEP Combined - 01

14 Fermiophobic Upper Limit on B(h 0!"")#(e + e -! h 0 Z)/#(SM) LEP Combined Excluded Region Fermiophobic BR Limit = GeV Expected Limit = GeV

15 Only Searches so far... h invisible h jj h V V h γγ h 2φ 4b Excludes: m h < 114 GeV m h < 113 GeV m h < GeV m h < 117 GeV m h < 110 GeV h X (leptonic Z) m h < 82 GeV

16 Non-standard Higgs Decays Limit on k OPAL!s!" = 91, GeV Observed Expected (CL=95%) m S 0 (GeV)

17 95% CL limit on! (a) SM Higgs LEP "s = GeV Observed Expected for background Must suppress the BR to standard model modes to ~20% m H (GeV/c 2 )

18 Non-standard Higgs Decays Most problematic decay: h N jets At the LHC, one would still look for SM decays to γγ, V V, with S/ B 8, 5 20 (SM values) reduced (100 fb -1 ). E. Berger, C.-W. Chiang, J. Jiang, T. Tait, C. Wagner - 02

19 Alternative phenomenology of NMSSM (generalized): the Higgs Add a singlet superfield to the spectrum - helps add to the Higgs mass and adds the possibility of h aa XX h ss XX h ss 4a 4X where the X is 2b s, 2 taus or 2 unflavored jets. J. Gunion, H. Haber, T. Moroi - 96 B. Dobrescu and K. Matchev - 00 R. Dermisek and J. Gunion - 04 S. Chang, P. Fox, N. Weiner - 05

20 Time to loosen up

21 Unified Gaugino Masses M 1 M 2 = 5 3 tan2 θ w 1 2

22 Unified Gaugino Masses M 1 M 2 = 5 3 tan2 θ w 1 2 Anomaly Mediation: M 1 = β g /g M 2 β g /g 3 Dirac Gauginos: M 1 M 2 = ( ) 2 ( ) 1 α2 b (µ) 2 α1 2 (µ) 3 α 2 (M GUT ) α 2 (µ) 8 [for SU(5)] Orbifold GUTs : M 1 M 2 = arbitrary

23 A Supersymmetric Standard Model W = H 1 QD c + H 2 QU c + H 1 LE c + µh 1 H 2 +LQD c + U c D c D c + LLE c + µ L LH 2

24 A Supersymmetric Standard Model W = H 1 QD c + H 2 QU c + H 1 LE c + µh 1 H 2 +LQD c + U c D c D c + LLE c + µ L LH 2 Could have Baryon Parity.

25 A Supersymmetric Standard Model W = H 1 QD c + H 2 QU c + H 1 LE c + µh 1 H 2 +LQD c + U c D c D c + LLE c + µ L LH 2 or Lepton Parity p X X must have an odd number of fermions, thus its lepton number L = 2n + 1. No lepton parity violation, no decay.

26 Bounds on R-parity violation λ ijku c i D c jd c k λ uds, λ udb < 10 7, 10 4 λ usb, λ cds, λ cdb, λ csb < 1 (λ ijkλ i j k ) < double nucleon decay, n - n oscillations unitarity... rare decays, e.g., hadronic B s assuming 100 GeV squarks easily allows the spurion mnemonic λ ijk y i y j y k

27 Higgs decays with B-violation χ q h χ q q q q q higgs -> 6 jets! m h > 82 GeV

28 Neutralino Decay χ q q q q λ > 0.01 and squark masses < 600 GeV for fast decays

29 Neutralino Decay Length λ m χ = 25GeV m χ = 35GeV mm 4 cm 1 m TeV

30 Allowed Higgs Masses tan β Scanning M 1, M 2, µ, tan β 110 GeV 96 GeV 87 GeV 93 GeV µ

31 LEP I Constraints Z couples due to mixing of neutralinos. Typically add about 2 MeV to the width. χ 2 1 (Thanks Tim!)

32 Allowing a Lighter Higgs Improves the Fit χ 2 0.5

33 Search for RPV SUSY (Delphi)

34 Search for RPV SUSY (Delphi) Assumed Gaugino Mass Unification: M 1 = 5 3 tan θ W 2 M 2

35 Search for RPV SUSY (Delphi)

36 Squark Searches Require large missing energy cuts (>100 GeV)!

37 Squark Search with B-violation No sensitivity for sbottoms

38 Squark Search with B-violation No sensitivity for sbottoms Mixed to decouple from the Z boson

39 Light Sbottoms??? Patrick Janot, 2004

40 Higgs to Light Sbottoms q b h q b q q q = s, d q = c, u

41 Higgs to Light Sbottoms q h Γ h b1 b 1 b 2G F (m b µ tan βs bc b) 2 8πm h q Large tan β, m h > 82 GeV b q q Carena, Heinemeyer, Wagner, Weiglein (2000)

42 Sbottom Mass Matrix ( m 2 L m b (A b + µ tan β) m b (A b + µ tan β) m 2 R ) Diagonal terms GeV (squared) requires few-10% tuning to get light enough sbottom.

43 Lepton Number Violation χ ν, τ b b, c ν, τ

44 Typical Bounds on Superpartners with B Violation ẽ R, µ R, τ R 94, 85, 70 (A) ν 88, 65, 65 (A) ũ L,R, d L,R 87, 80, 86, 56 (L) t 1, b 1 77(88), (78)(O, D) t 1, b 1 77, 55 (L)

45 Conclusions Did we miss the Higgs at LEP? A Higgs which decays to a multi-jet final state happens in SUSY parameter space and allows mh ~ mz. LEP analyses should continue! There are Higgses that LEP can see and the LHC can t. We are now exploring a Tevatron study.