Beyond the Standard Model

Transcription

1 Beyond the Standard Model neutrinos axions GUTs extra dimensions: LED, RS little Higgs supersymmetry Howard Baer University of Oklahoma Howard Baer, CIPANP meeting, San Diego, CA, May 26,

2 The Standard Model of Particle Physics gauge symmetry: SU(3) C SU(2) L U(1) Y g, W ±, Z 0, γ matter content: 3 generations quarks and leptons u d u R, d R ; ν e, e R (1) L Higgs sector spontaneous electroweak symmetry breaking: φ = φ+ φ 0 L (2) massive W ±, Z 0, quarks and leptons L = L gauge + L matter + L Y uk. + L Higgs : 19 parameters good-to-excellent description of (almost) all accelerator data! Howard Baer, CIPANP meeting, San Diego, CA, May 26,

3 Shortcomings of SM Data neutrino masses and mixing baryogenesis (matter anti-matter asymmetry) cold dark matter dark energy Theory quadratic divergences in scalar sector fine-tuning origin of generations explanation of masses/ mixing angles origin of gauge symmetry/ quantum numbers unification with gravity Howard Baer, CIPANP meeting, San Diego, CA, May 26,

4 The neutrino revolution: 1999 today Solar ν problem: Davis-Bahcall confirmed: Gallex, SAGE SuperK atmos. oscillations SNO ν NC observations MINOS KamLand K2K m 2 [ev 2 ] KARMEN2 Cl 95% NOMAD MiniBooNE Ga 95% Bugey K2K CHOOZ ν e ν X ν µ ν τ NOMAD all solar 95% SNO 95% CDHSW CHORUS NOMAD CHORUS LSND 90/99% SuperK 90/99% PaloVerde MINOS KamLAND 95% Super-K 95% ν e ν τ ν e ν µ All limits are at 90%CL unless otherwise noted tan 2 θ 10 2 Howard Baer, CIPANP meeting, San Diego, CA, May 26,

5 Interpretation: massive νs and oscillations SuperK/K2K/Minos atm osc.: νs oscillate: are massive! m 2 atm ev 2 θ atm 45 Solar ν problem MSW matter oscillations ν e (r = 0) ν 2 (r = R ) measure ν e content of ν 2 m ev 2 θ 30 Howard Baer, CIPANP meeting, San Diego, CA, May 26,

6 ν questions what is absolute m νi? is ν spectra normal or inverted? are νs Majorana or Dirac? what is θ 13? CP violation in PMNS mixing matrix? interpretation in terms of see-saw: m νi (f νi v) 2 /M N what is M Ni scale? implications for GUTs disparate scales: m weak and M Ni M GUT? implications for leptogenesis Howard Baer, CIPANP meeting, San Diego, CA, May 26,

7 Axions L QCD g2 θ s 32π F µν 2 A F Aµν : expect θ 1 but θ < 10 9 Peccei-Quinn solution to strong CP problem in QCD: a(x) pseudo-goldstone boson from PQ breaking at scale f a GeV f a /N (GeV) non-thermally produced via vacuum mis-alignment as cold DM m a Λ 2 QCD /f a ev [ ] 7/6 Ω a h ev 2 m a h 2 astro bound: stellar cooling m a < 10 1 ev a couples to EM field: a γ γ coupling (Sikivie) Ω a h 2 (vacuum mis-alignment) WMAP 5: Ω CDM h 2 = ± m a (ev) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

8 Axion microwave cavity searches ongoing searches: ADMX experiment Livermore U Wash. Phase I: probe KSVZ for m a ev Phase II: probe DFSZ for m a ev beyond Phase II: probe higher values m a Howard Baer, CIPANP meeting, San Diego, CA, May 26,

9 Grand unified theories: SU(5) unify SU(3) C SU(2) L U(1) Y into SU(5): single coupling constant: g 5 SU(5) SU(3) C SU(2) L U(1) Y at Q = M GUT GeV new X µ, Y µ gauge bosons predict p-decay: τ p years experiment: τ p > years (rule out simplest models) partial matter unification d c R, ǫab L b 5 of SU(5) Q a, u c R, ec R 10 of SU(5) Charge quantization: Q(e ) = 3Q(d R )! m b 3m τ (true) doublet-triplet splitting: 5 H φ SM, H c gauge hierarchy problem: m H M GUT fine-tune 1 : Howard Baer, CIPANP meeting, San Diego, CA, May 26,

10 Grand unified theories: SO(10) unify SU(3) C SU(2) L U(1) Y into S0(10) 45 gauge bosons complete matter unification of each generation conjugate spinor reps 16 and of SU(5) all matter unified! 1 occupied by ν R SO(10) breaking M Ni (Majorana): see-saw m ν explain anomaly cancellation for SM and SU(5) still suffers from gauge hierarchy problem main idea probably right; implementation probably wrong Howard Baer, CIPANP meeting, San Diego, CA, May 26,

11 Large extra dimensions (LED or ADD) assume SM lies on 3-brane surface embedded in d = 4 + n-dim l bulk fundamental scale in d-dim s: M =? fundamental scale in 3-brane: M P = GeV compactify n-dim s on e.g. a torus MP 2 = Mn+2 V n where V n is volume of extra dim s for n > 2, then M m weak allowed! Sol n to hierarchy problem? But then why r Pl r c? Howard Baer, CIPANP meeting, San Diego, CA, May 26,

12 LED phenomenology compactification KK-excited gravitons g n µν: only g 0 µν is massless couple to matter 1/M P KK-graviton mass splitting: tiny tiny graviton emission cross-section compensated by vast number of graviton emissions possible: M P factors cancel! can see e.g. pp g + g n µν at LHC! can observe quantum gravity at colliders! also, black hole production? Howard Baer, CIPANP meeting, San Diego, CA, May 26,

13 KK-graviton prod n at LHC Howard Baer, CIPANP meeting, San Diego, CA, May 26,

14 Warped extra dimensions (Randall-Sundrum RS) assume SM and hidden branes separated in warped (AdS 5 ) spacetime warped metric: ds 2 = e 2kr cφ η µν dx µ dx ν + r 2 cdφ 2 solve Einstein eq ns in 5-d; compactify 5th dim n on an orbifold find m weak = e kr cπ M P weak scale emerges as exponential suppression of Planck scale consequence: KK-excited gravitons with weak scale coupling and TeV-scale mass splitting! can see excited graviton resonances at colliders! Howard Baer, CIPANP meeting, San Diego, CA, May 26,

15 RS phenomenology Davoudiasl, Hewett, Rizzo KK-excited gravitons: weak scale mass spacing via zeros of Bessel functions can produce RS gravitons at e + e or hadron colliders massive graviton resonances couple to all matter pairs Howard Baer, CIPANP meeting, San Diego, CA, May 26,

16 Little Higgs theories New approach to EWSB: Arkani-Hamed, Cohen, Georgi, 2001 Higgs field arises as pseudo-nambu-goldstone boson from collective symmetry breaking Symmetry quadratic divergences to m 2 H higher quad. divergences remain) cancel at 1-loop (2-loop and Natural cut-off of theory is 10 TeV to avoid little hierarchy problem All LH theories predict new particles at 1-10 TeV scale new gauge bosons A H, W ± H, W 0 H to cancel gauge boson loops in m2 H new top partner fermions T to cancel top loop in m 2 H new scalars to cancel Higgs self coupling loops precise details model-dependent: most popular: littlest Higgs with SU(5)/SO(5) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

17 Spectrum from Little Higgs theories φ 0 φ + φ ++ W H Z H T 1 TeV A H h W,Z γ t scalar sector gauge sector top sector Howard Baer, CIPANP meeting, San Diego, CA, May 26,

18 T-parity in Little Higgs theories (LHT) It was found that LH models tend to give large corrections to precision EW observables unless m LH 10 TeV This re-introduces fine-tunings in Higgs sector EWPOs can be saved by introducing T-parity (Cheng and Low) SM particles: t-even new GBs, scalars, some top-partners: t-odd then contributions to EWPOs only occur at loop level can allow much lighter new particle states t-odd particles produced in pairs todd particles decay to other t-odd states Lightest t-odd particle absolutely stable: DM candidate, usually A H (but see Hill+Hill anomalies paper) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

19 LHT models at LHC main search channel: pp T T with T ta H search for t t+ E T states see Cheng, Low and Wang, PRD74, (2006) Matsumoto, Nojiri, Nomura, PRD75, (2007) Belyaev, Chen, Tobe and Yuan, PRD74, (2006) Carena, Hubisz, Perelstein, Verdier, PRD75, (2007) Han, Mahbubani, Walker, Wang, arxiv: (2008) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

20 T T discovery at LHC Han, Mahbubani, Walker, Wang, arxiv: (2008) significance after cuts with 100 fb 1 at LHC 1200 FERMIONIC TOP PARTNER MAH MT Howard Baer, CIPANP meeting, San Diego, CA, May 26,

21 Supersymmetry (SUSY) This symmetry is similar to non-abelian gauge symmetry except that: transformation is e iᾱq, where Q is a (Majorana) spinor generator, and α is a spinorial set of parameters with ᾱ = α γ 0 SUSY transforms bosons fermions SUSY is a spacetime symmetry: the square-root of a translation action is invariant under SUSY, but not Lagrangian (total derivative) Can construct SUSY gauge theories Can construct (softly broken) SUSY SM: MSSM Solves problem of SM scalar fields: cancellation of quadratic divergences allows for stable theories with vastly different mass scales: e.g. M weak 10 3 GeV and M GUT GeV local SUSY where α(x) spacetime dependent: supergravity and GR (but non-renormalizable; go to string theory?) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

22 Minimal Supersymmetric Standard Model (MSSM) Adopt gauge symmetry of Standard Model: SU(3) C SU(2) L U(1) Y gauge boson plus spin 1 2 gaugino gauge superfield SM fermions chiral scalar superfields: scalar partner for each SM fermion helicity state electron ẽ L and ẽ R two Higgs doublets to cancel triangle anomalies: H u and H d add all admissible soft SUSY breaking terms resultant Lagrangian has 124 parameters! Lagrangian yields mass eigenstates, mixings, Feynman rules for scattering and decay processes predictive model! Howard Baer, CIPANP meeting, San Diego, CA, May 26,

23 Physical states of MSSM: usual SM gauge bosons, quarks and leptons gluino: g bino, wino, neutral higgsinos neutralinos: Z1, Z 2, Z 3, Z 4 charged wino, higgsino charginos: W ± 1, W ± 2 squarks: ũ L, ũ R, d L, d R,, t 1, t 2 sleptons: ẽ L, ẽ R, ν e,, τ 1, τ 2, ν τ Higgs sector enlarged: h, H, A, H ± a plethora of new states to be found at LHC! Howard Baer, CIPANP meeting, San Diego, CA, May 26,

24 Supergravity (SUGRA) e iᾱq with α(x): local SUSY transformation forces introduction of spin 2 graviton and spin 3 2 gravitino resultant theory General Relativity in classical limit! rules for Lagrangian in supergravity gauge theory: Cremmer et al. (1983) fertile ground: supergravity grand unification: LE limit of superstring? minimal supergravity model (msugra) m 0, m 1/2, A 0, tan β, sign(µ) m 0 = mass of all scalars at Q = M GUT m 1/2 = mass of all gauginos at Q = M GUT A 0 = trilinear soft breaking parameter at Q = M GUT tanβ = ratio of Higgs vevs µ = SUSY Higgs mass term; magnitude determined by REWSB! Howard Baer, CIPANP meeting, San Diego, CA, May 26,

25 Some successes of SUSY GUT theories SUSY divergence cancellation maintains hierarchy between GUT scale Q = GeV and weak scale Q = 100 GeV gauge coupling unification! Howard Baer, CIPANP meeting, San Diego, CA, May 26,

26 Gauge coupling evolution Howard Baer, CIPANP meeting, San Diego, CA, May 26,

27 Some successes of SUSY GUT theories SUSY divergence cancellation maintains hierarchy between GUT scale Q = GeV and weak scale Q = 100 GeV gauge coupling unification! Lightest Higgs mass m h < 135 GeV as indicated by radiative corrections! Howard Baer, CIPANP meeting, San Diego, CA, May 26,

28 Precision electroweak data and the Higgs mass: experimental errors 68% CL: LEP2/Tevatron (today) Tevatron/LHC light SUSY M W [GeV] M H = 114 GeV SM M H = 400 GeV SM MSSM both models MSSM heavy SUSY Heinemeyer, Hollik, Stockinger, Weber, Weiglein m t [GeV] S. Heinemeyer et al. Howard Baer, CIPANP meeting, San Diego, CA, May 26,

29 Some successes of SUSY GUT theories SUSY divergence cancellation maintains hierarchy between GUT scale Q = GeV and weak scale Q = 100 GeV gauge coupling unification! Lightest Higgs mass m h < 130 GeV as indicated by radiative corrections! radiative breaking of EW symmetry if m t GeV! Howard Baer, CIPANP meeting, San Diego, CA, May 26,

30 Soft term evolution and radiative EWSB Howard Baer, CIPANP meeting, San Diego, CA, May 26,

31 Some successes of SUSY GUT theories SUSY divergence cancellation maintains hierarchy between GUT scale Q = GeV and weak scale Q = 100 GeV gauge coupling unification! Lightest Higgs mass m h < 130 GeV as indicated by radiative corrections! radiative breaking of EW symmetry if m t GeV! dark matter candidate: lightest neutralino Z 1 stablize neutrino see-saw scale vs. weak scale SO(10) SUSY GUT: baryogenesis via leptogenesis can give dark energy via CC Λ (but need huge fine-tuning...) SUGRA = low energy limit of superstring? stringy multiverse: anthropic selection of small CC? Howard Baer, CIPANP meeting, San Diego, CA, May 26,

32 Evidence for dark matter in the universe binding of galactic clusters (Zwicky, 1930s) galactic rotation curves large scale structure formation inflation Ω = ρ/ρ c = 1 gravitational lensing anisotropies in cosmic MB (WMAP) surveys of distant galaxies via SN (DE) Big Bang nucleosynthesis Ω Λ 0.7 Ω CDM 0.25 Ω baryons (dark baryons 0.040) Ω ν Howard Baer, CIPANP meeting, San Diego, CA, May 26,

33 SUSY dark matter R-parity conservation conserved B and L proton stability R(particle) = 1; R(sparticle) = 1 Naturally occurs in SO(10) SUSY GUT theories Some consequences: Sparticles are produced in pairs Sparticles decay to other sparticles Lightest SUSY particle (LSP) is absolutely stable (good candidate for dark matter) LSP must be charge, color neutral (bound on cosmological relics) lightest neutralino Z 1 is WIMP candidate axion/axino multiplet gravitino Howard Baer, CIPANP meeting, San Diego, CA, May 26,

34 Calculating the relic density of neutralinos At very high T, neutralinos in thermal equilibrium with cosmic soup As universe expands and cools, expansion rate exceeds interaction rate (freeze-out) number density is governed by Boltzmann eq. for FRW universe dn/dt = 3Hn σv rel (n 2 n 2 0) ( ) 1/2 Ω ez1 h 2 = s 0 45 xf 1 ρ c /h 2 πg m P l σv Ω CDM h σv 0.9 pb! σv = πα 2 /8m 2 m 100 GeV The WIMP miracle! : cosmic motivation for new physics at weak scale SUSY: 1722 annihilation/co-annihilation reactions; 7618 Feynman diagrams IsaReD program (HB, A. Belyaev, C. Balazs) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

35 Results of χ 2 fit using τ data for a µ : not LSP msugra with tanβ = 10, A 0 = 0, µ > not LSP msugra with tanβ = 54, A 0 = 0, µ > Ζ ~ Ζ ~ 1 10 m 1/2 (GeV) No REWSB m 0 (GeV) m h =114.1GeV LEP2 excluded SuperCDMS CDMSII CDMS ln(χ/dof) m 1/2 (GeV) No REWSB m 0 (GeV) m h =114.1GeV LEP2 excluded SuperCDMS CDMSII CDMS ln(χ 2 /DOF) HB, C. Balazs: JCAP 0305, 006 (2003) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

36 Production of sparticles at CERN LHC Howard Baer, CIPANP meeting, San Diego, CA, May 26,

37 Sparticle cascade decays Mass scale (GeV) g ~ (2060) q ~ L ( 1857) q ~ R ( 1770) b ~ 2 (1690) t ~ 2 (1689) b ~ 1 (1619) 1400 t ~ 1 (1449) W ~ ± 2 (1067) Z ~ 4 (1066) Z ~ 3 (1056) W ~ ± 1 (754) Z ~ 2 (754) τ ~ 2 (726) ν ~ τ (712) 400 τ ~ 1 (442) Z ~ 1 (395) Br (%) Z ~ 1 qq (27.0 %) Z ~ 1 τνwbb (12.1 %) Z ~ 1 ττwwbb (8.4 %) Z ~ 1 WWbb (7.4 %) Z ~ 1 τνqq (5.9 %) Z ~ 1 τνwwwbb (4.1 %) Z ~ 1 ττbb (2.9 %) Z ~ 1 ττqq (2.9 %) Z ~ 1 τνzwbb (2.8 %) Z ~ 1 τνhwbb (2.6 %) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

38 Event generation for sparticles p 2 ~ g 3 ~ Z 1 1 ~ q Hadrons 4 ~ Z 1 p Remnants 5 Event generation in LL - QCD 1) Hard scattering / convolution with PDFs 2) Intial / final state showers 3) Cascade decays 4) Hadronization 5) Beam remnants Howard Baer, CIPANP meeting, San Diego, CA, May 26,

39 Simulated sparticle production event at LHC GEANT figure msugra : ~ g m 0 = 1000 GeV, m 1/2 = 500 GeV, A 0 = 0, ~ t1 t tan β = 35, µ > 0 ~ ul ~ Z 2 + u ( jet6, E T = 1196 GeV) ~ - Z1 + h W + b ( jet4, E T = 113 GeV) b ( jet1, E = 206 GeV) s ( jet5, E T = 79 GeV) + c - ( jet2, E T = 320 GeV) ~+ b T ( jet3, E = 536 GeV) + b W2 ~+ -T W1 + Z νν ~ + + miss Z1 + W τ ν E T = 380 GeV + e ν ~ Z1 b-jet 2 b-jet 1 m ~g = 1266 GeV m ~u = 1450 GeV b-jet 3 L m ~t = 1026 GeV 1 m ~Z = 410 GeV 2 m Z~ = 214 GeV 1 jet 6 m h = 119 GeV S. Abdullin, A. Nikitenko b-jet 4 jet 5 ~ Z1 S. Abdullin Oct Howard Baer, CIPANP meeting, San Diego, CA, May 26,

40 Sparticle reach of all colliders with relic density 1600 msugra with tanβ = 10, A 0 = 0, µ > 0 Ωh 2 < LEP2 excluded 1600 msugra with tanβ = 45, A 0 = 0, µ < 0 Ωh 2 < LEP2 excluded m 1/2 (GeV) LHC m 1/2 (GeV) LHC 600 LC LC LC LC Tevatron 200 Tevatron m 0 (GeV) m 0 (GeV) HB, Belyaev, Krupovnickas, Tata: JHEP 0402, 007 (2004) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

41 Precision measurements at LHC: Atlas and CMS M eff = E T + E T (j1) + + E T (j4) sets overall m g, m q scale m(l l) < m ez2 m ez1 mass edge m(l l) distribution shape combine m(l l) with jets to gain m(l lj) mass edge: info on m q further mass edges possible e.g. m(l ljj) Higgs mass bump h b b likely visible in E T + jets events in favorable cases, may overconstrain system for a given model methodology very p-space dependent some regions are very difficult e.g. HB/FP Howard Baer, CIPANP meeting, San Diego, CA, May 26,

42 Direct detection of SUSY DM Direct search via neutralino-nucleon scattering Howard Baer, CIPANP meeting, San Diego, CA, May 26,

43 Direct detection of neutralino DM: the race is on! Cross-section [pb] (normalised to nucleon) WIMP Mass [GeV/c 2 ] Gaitskell,Mandic,Filippini DATA listed top to bottom on plot Edelweiss I final limit, 62 kg-days Ge limit DAMA k kg-days NaI Ann. Mod. 3sigma w/dama 1996 WARP 2.3L, 96.5 kg-days 55 kev threshold CDMS 2008 Ge CDMS: (reanalysis) Ge XENON (Net 136 kg-d) CDMS Soudan 2007 projected SuperCDMS (Projected) 2-ST@Soudan WARP 140kg (proj) SuperCDMS (Projected) 25kg (7-ST@Snolab) XENON100 (150 kg) projected sensitivity LUX 300 kg LXe Projection (Jul 2007) XENON1T (proj) Baer et. al Howard Baer, CIPANP meeting, San Diego, CA, May 26,

44 Indirect detection (ID) of SUSY DM: ν-telescopes Z 1 Z1 b b, etc. in core of sun (or earth): ν µ µ in ν telescopes Amanda, Icecube, Antares Howard Baer, CIPANP meeting, San Diego, CA, May 26,

45 ID of SUSY DM: γ and anti-matter searches Z 1 Z1 q q, etc. γ in galactic core or halo Z 1 Z 1 q q, etc. e + in galactic halo Z 1 Z 1 q q, etc. p in galactic halo Z 1 Z1 q q, etc. D in galactic halo Howard Baer, CIPANP meeting, San Diego, CA, May 26,

46 Direct and indirect detection of neutralino DM 1600 msugra, A 0 =0 tanβ=10, µ> msugra, A 0 =0, tanβ=50, µ< not LSP Z ~ 1 LHC DD µ 1200 not LSP Z ~ 1 DD m 1/2 (GeV) m 1/2 (GeV) LHC 600 LC LC LC LC500 µ 200 TEV LEP no REWSB 200 LEP no REWSB m 0 (GeV) Φ(p - )=3x10-7 GeV -1 cm -2 s -1 sr -1 Φ(γ)=10-10 cm -2 s -1 Φ sun (µ)=40 km -2 yr -1 (S/B) e+ =0.01 m h =114.4 GeV m 0 (GeV) Φ(p - ) 3e-7 GeV -1 cm -2 s -1 sr -1 (S/B) e+ =0.01 Φ(γ)=10-10 cm -2 s -1 Φ sun (µ)=40 km -2 yr -1 m h =114.4 GeV 0<Ωh 2 <0.129 σ(z ~ 1 p)=10-9 pb Φ earth (µ)=40 km -2 yr -1 σ(z ~ 1 p)=10-9 pb 0< Ωh 2 < HB, Belyaev, Krupovnickas, O Farrill: JCAP 0408, 005 (2004) Howard Baer, CIPANP meeting, San Diego, CA, May 26,

47 Impact of DM direct/indirect detection on LHC program Extend reach in σ SI pb explore thoroughly region of MHDM, possibly MWDM after discovery, extract m wimp? m e Z 1 sets absolute mass scale for SUSY particles- combine with LHC mass edges to gain LHC absolute sparticle masses learn if Z 1 is absolutely stable: R-conservation IceCube turn-on can discover/verify especially MHDM knowledge of LHC spectra, σ SI, σ SD combined with possible gamma ray signals may allow map of dark matter distribution in the galaxy role of p, e +, D signals Howard Baer, CIPANP meeting, San Diego, CA, May 26,

48 Conclusion: We are entering a revolutionary period! I covered just a few of the new physics possibilities neutrino physics axions and strong CP problem extra dimensions little Higgs models supersymmetry in many guises: neutralino, axion/axino, gravitino as DM new facilities (LHC, ν exp ts, DM searches,...) should lead, in the next few years, to a new paradigm beyond the Standard Model for the laws of physics as we know them! Howard Baer, CIPANP meeting, San Diego, CA, May 26,