Beyond the Standard Paradigm

Transcription

1 Beyond the Standard Paradigm The standard paradigm or a landscape? Heavy Z Extended Higgs Neutralinos Quasi-chiral exotics

2 References J. Kang, P. Langacker, T. j. Li and T. Liu, Electroweak baryogenesis in a supersymmetric U() model, Phys. Rev. Lett. 94, 68 (5), hep-ph/486. J. Kang and P. Langacker, Z discovery limits for supersymmetric E(6) models, Phys. Rev. D 7, 354 (5), hep-ph/49. V. Barger, PL, H.S. Lee and G. Shaughnessy, Higgs Sector in Extensions of the MSSM, Phys. Rev. D 73, 5 (6), hep-ph/6347. V. Barger, P. Langacker and G. Shaughnessy, Neutralino signatures of the singlet extended MSSM, Phys. Lett. B 644, 36 (7), hep-ph/6968. V. Barger, P. Langacker and G. Shaughnessy, Collider signatures of singlet extended Higgs sectors, Phys. Rev. D 75, 553 (7), hep-ph/639. V. Barger, I. Lewis, M McCaskey, P. Langacker, G. Shaughnessy, and B. Yencho, Recoil detection of the lightest neutralino in MSSM singlet extensions, hepph/736. J. Kang, PL and B. Nelson, Quasi-Chiral Exotics, to appear.

3 The standard paradigm MSSM at TeV scale LSP WIMPs (Possibly) GUT at unification scale Gauge unification Seesaw model for m ν Leptogenesis (Possibly) GUT relations for couplings (large representations?) SUSY breaking in hidden sector

4 Beyond the MSSM Even if supersymmetry holds, MSSM may not be the full story Most of the problems of standard model remain, new ones introduced (FCNC, EDM) µ problem introduced: W µ = µĥ u Ĥ d, µ = O(electroweak) Ingredients of 4d GUTs hard to embed in string, especially large Higgs representations, Yukawa relations Remnants of GUT/Planck scale physics may survive to TeV scale Specific string constructions often have extended gauge groups, exotics, extended Higgs/neutralino sectors (Defect or hint?) Important to explore alternatives/extensions to MSSM

5 Remnants Physics from the Top-Down Z or other gauge Extended Higgs/neutralino (doublet, singlet) Quasi-Chiral Exotics Non-standard ν mass (enhanced symmetries) Quasi-hidden (Strong coupling? SUSY breaking? Composite family?) Charge / (Confinement?, Stable relic?) Time varying couplings LED (TeV black holes, stringy resonances) LIV, VEP (speeds, decays, (oscillations) of HE γ, e, gravity waves (ν s))

6 A TeV-Scale Z Strings, GUTs, DSB, little Higgs, LED often involve extra Z Typically M Z > 6 9 GeV (Tevatron, LEP, WNC); θ Z Z < few 3 (Z-pole) (CDF di-electron: 85 (Z seq ), 74 (Z χ ), 75 (Z ψ ), 745 (Z η )) Discovery to M Z 5 8 TeV at LHC, ILC, (pp µ + µ, e + e, q q) (depends on couplings, exotics, sparticles) Diagnostics to - TeV (asymmetries, y distributions, associated production, rare decays)

7 Implications of a TeV-scale U() Natural Solution to µ problem W hsh u H d µ eff ( stringy version of ) = h S Extended Higgs sector Relaxed upper limits, couplings, parameter ranges (e.g., tan β can be close to ) Higgs singlets needed to break U() Doublet-singlet mixing highly non-standard collider signatures Large A term and possible tree-level CP violation (no new EDM constraints) electroweak baryogenesis

8 Extended neutralino sector Additional neutralinos, non-standard couplings, e.g., light singlino-dominated, extended cascades Enhanced possibilities for cold dark matter, g µ (even small tan β) Exotics (anomaly-cancellation) May decay by mixing; by diquark or leptoquark coupling; or be quasi-stable Constraints on neutrino mass generation Z decays into sparticles/exotics Flavor changing neutral currents (for non-universal U() charges) Tree-level effects in B decay competing with SM loops (or with enhanced loops in MSSM with large tan β)

9 Extended Higgs Sector Standard model singlets S i and additional doublet pairs H u,d very common. Additional doublet pairs Richer spectrum, decay possibilities May be needed (or expand possibilities for) quark/lepton masses/mixings (e.g., stringy symmetries may restrict single Higgs couplings to one or two families) Extra neutral Higgs FCNC (suppressed by Yukawas) Significantly modify gauge unification (unless compensated)

10 Higgs singlets S i Standard model singlets extremely common in string constructions Needed to break extra U() gauge symmetries Solution to µ problem (U(),, nmssm, smssm) W h s ŜĤ u Ĥ d µ eff = h s S Relaxed upper limits, couplings, parameter ranges (e.g., tan β = v u /v d can be close to ), singlet-doublet mixing Large A term and possible tree-level CP violation electroweak baryogenesis

11 Dynamical µ V. Barger, PL and H. S. Lee, Lightest neutralino in extensions of the MSSM, Phys. Lett. B 63, 85 (5), hep-ph/587 V. Barger, PL, H.S. Lee and G. Shaughnessy, Higgs Sector in Extensions of the MSSM, Phys. Rev. D 73, 5 (6), hep-ph/6347. V. Barger, P. Langacker and G. Shaughnessy, Neutralino signatures of the singlet extended MSSM, Phys. Lett. B 644, 36 (7), hep-ph/6968. V. Barger, P. Langacker and G. Shaughnessy, Collider signatures of singlet extended Higgs sectors, Phys. Rev. D 75, 553 (7), hep-ph/639. V. Barger, I. Lewis, M McCaskey, P. Langacker, G. Shaughnessy, and B. Yencho, Recoil detection of the lightest neutralino in MSSM singlet extensions, hep-ph/736. Abel, Bagger, Barger, Bastero-Gil, Batra, Birkedal, Carena, Chang, Choi, Cvetic, Dedes, Delgado, Demir, Dermisek, Dobrescu, Drees, Ellis, Ellwanger, Erler, Espinosa, Everett, Fox, Godbole, Gunion, Haber, Han, Hooper, Hugonie, Kaplan, King, Landsberg, Li, Matchev, McElrath, Menon, Miller, Moretti, Morrissey, Nevzorov, Panagiotakopoulos, Perelstein, Pilaftsis, Poppitz, Randall, Rosner, Roy, Sarkar, Sopczak, Tait, Tamvakis, Vempati, Wagner, Weiner, White, Zerwas, Zhang

12 Models with Dynamical µ Model Symmetry Superpotential CP-even CP-odd MSSM µĥ u Ĥ d H, H A Z 3 h s ŜĤ u Ĥ d + κ 3 Ŝ3 H, H, H 3 A, A nmssm Z R 5, ZR 7 h s ŜĤ u Ĥ d + ξ F M nŝ H, H, H 3 A, A U() h s ŜĤ u Ĥ d H, H, H 3 A smssm U() h s ŜĤ u Ĥ d + λ s Ŝ Ŝ Ŝ 3 H, H, H 3, A, A, A 3, A 4 H 4, H 5, H 6 MSSM: gaugino unification but general µ ( cubic ): may be domain wall problems (Z R ) nmssm ( tadpole ): no domain walls; tadpoles from high order : additional Z (µ eff, M Z generated by single S) smssm: stringy w. decoupled µ eff, M Z (Ĥ u, Ĥ d, Ŝ reduces to nmssm in S i decoupling limit )

13 A Unified Analysis of Higgs and Neutralino Sectors V F = h s H u H d +ξ F M n +κs + h s S ( H d + H u ) V D = G 8 + g ( Hd H u ) g ( + Hd H u H u H d ) ( QHd H d + Q Hu H u + Q S S ) V soft = m d H d + m u H u + m s S + (A s h s SH u H d + κ3 ) A κs 3 +ξ S M 3n S + h.c. black = MSSM (with µ = h s S ); blue= extensions; cyan = ; magenta = ; red=

14 Mass matrices in {H d, H u, S} basis CP-even (tree level) ( H u,d v u,d/, S s/ ) (M + ) dd = (M + ) du = (M + ) ds = (M + ) uu = (M + ) us = " # G 4 + Q H g d v d + (h sa s " # G 4 + h s + Q H d Q H ug hh s + Q Hd Q S g i " G 4 + Q Hu g # hh s + Q HuQ S g i v d s ( h sa s v u + (h sa s v u s ( h sa s + h sκs + h sξ F M n s v d v u ( h sa s + h s κs)v u + h sκs ) v us v d + h sκs + h sξ F M n s + h s κs)v d ) v ds v u + h sξ F M n s )s (M + ) ss = h Q S g + κ i s + ( h sa s ξs M 3 n v d v u ) v dv u s + κa κ s

15 Also CP-odd and charged Higgs (CP breaking ignored) Leading loop corrections (top-stop loops) are universal Theoretical upper limits on H MSSM M H relaxed ( smaller tan β allowed) M Z cos β + M () M () = (M () + ) dd cos β + (M () + ) uu sin β + (M () + ) du sin β,, and Peccei-Quinn limits M H M Z cos β + h s v sin β + M () M H M Z cos β+ h s v sin β+g Z v (Q Hd cos β+q H u sin β) + M ()

16 Experimental LEP SM and MSSM bounds may be relaxed by singlet-doublet mixing (also by nonstandard decays) ξ ZZH.. MSSM LEP limit 95% C.L M H (GeV) Reduced ZZH i coupling.8 ξ ZZHi = (R i + cos (β α).6.4 mass,. Z Z mixing, cos β+ri + MSSM sin β) Also, Z HA, Z width, χ ± V minimum, RGE M A (GeV) (a) (b) ( SM ) SM

17 tan β 5 M h

18 Limiting Cases MSSM limit (s with µ eff = h s s/ fixed) two MSSM-like CP-even Higgs and one largely singlet (heavy in, light in, depends on κ in ) PQ and R limits (massless pseudoscalar) Model Limits Symmetry Effects MSSM B U() P Q M A κ, A κ U() P Q M A A s, A κ U() R M A ξ F, ξ S U() P Q M A g U() M Z, M A

19 CP Even CP Odd Higgs Mass (GeV) 5 5 MSSM PQ Limit s = 5 GeV Higgs Mass (GeV) 5 5 MSSM PQ Limit s = 5 GeV tan β tan β (a) (b) CP Even CP Odd Higgs Mass (GeV) 5 5 MSSM PQ Limit tan β = Higgs Mass (GeV) MSSM PQ Limit tan β = s (GeV) (c) s (GeV) (d) A s = M n = 5 GeV, A κ = 5 GeV, h s = κ =.5, ξ F,S =. FIG. : Lightest CP-even and lightest CP-odd Higgs masses vs. tan β and s for the MSSM,,,, and the PQ limits. Only the theoretical constraints are applied with s = 5 GeV (for tan β-varying curves), tan β = (for s-varying curves). Input parameters of A s = 5 GeV, A t = TeV, M Q = MŨ = TeV, κ =.5, A κ = 5 GeV, M n = 5 GeV,

20 ξ MSSM H H H 3 A A ξ MSSM H H H 3 A A.. Higgs Mass (GeV) Higgs Mass (GeV) (a) (b) Lightest Higgs ξ MSSM H H H 3 A ξ MSSM Higgs Mass (GeV) (c) Higgs Mass (GeV) (d) FIG. 4: Higgs masses vs. MSSM fraction ξ H i MSSM = P u ξ MSSM in the (a), (b), j=d (Rij + (c) ) and (d) the lightest CP-even Higgs of all extended models. The vertical line is the LEP lower bound on the Columbia MSSM (May (SM-like) 7, 7) Higgs mass.

21 CP-Even Higgs Mass Range CP-Odd Higgs Mass Range MSSM Scan Scan LEP 9 Th. 35 Th. 64 Th. 7 LEP MSSM 94 Th. State Crossing 63 Th. State Crossing 7 Scan 685 LEP & α ZZ 9 Th. 73 LEP & α ZZ 93 Scan Higgs Mass (GeV) 4 6 Higgs Mass (GeV) Charged Higgs Mass Range LEP MSSM 79 LEP 83 LEP 8 LEP 8 Scan 48 Scan 359 Scan 6873 Scan Higgs Mass (GeV) FIG. : Mass ranges of the lightest CP-even and CP-odd and the charged Higgs bosons in each

22 .8 H MSSM H H H.6 ξ Statistical Significance (H ) Production and decay rates modified. decays, H χ χ (or AA), via WBF (ξ >.5). Standard Model modes (5σ), vs invisible

23 Lightest Neutralino Mass matrix (M χ ) in basis { B, W 3, H, H, S, Z }: M g v / g v / M g v / g v / g v / g v / µ eff µ eff v /s g Z Q H v g v / g v / µ eff µ eff v /s g Z Q H v µ eff v /s µ eff v /s κs gz Q S s g Z Q H v g Z Q H v g Z Q S s M ( S s, H i v i, p v + v v 46 GeV, Q φ = φ U() charge) (black = MSSM; blue= extensions; cyan = ; magenta = )

24 M χ es, e Z = ± g Q Ss. (3) 7 5 Neutralino Mass (GeV) M χ6 ~.9 TeV B W 3 H H S Z Neutralino Mass (GeV) 4 3 B W 3 H H S Z MSSM MSSM (a) (nearly) decoupled singlino (b) strongly mixed singlino FIG. : Illustrative neutralino composition for the models in (a) a decoupled singlino scenario and (b) a strongly mixed singino scenario. Here, the MSSM contains a light Bino and Wino and heavy Higgsinos. The has a similar spectrum, but contains an additional heavy neutralino while the has a very light extra neutralino. The has two additional neutralinos that can intermix; their masses are strongly dependent on the singlet Higgs charge under the U() symmetry and the corresponding gaugino mass value. Common parameters used for this

25 N 5 N 5.8 N 5 N 5.8 N 5 N 5.6 N 6.6 N 6 N i.4 N i χ Mass (GeV) (a) χ Mass (GeV) (b) singlino and gaugino fractions of χ, N 35 N 55.8 N 35 N 35.8 N 55 N 65 N 3i.6.4 N 36 N 5,6i.6.4 N 66..

26 .8 MSSM.8 MSSM Bf(χ --> Z χ ).6.4 Bf(χ --> H χ ) χ Mass (GeV) χ Mass (GeV) (a) branching fractions of χ (Z, H ) χ (b).8 MSSM.8 MSSM Bf(χ 3 --> χ Z).6.4 Bf(χ 3 --> χ H ).6.4..

27 sleptons are heavy, most trilepton events will be from chargino and neutralino production via the s-channel W ± process. Some of the contributing neutralino and chargino decays to multileptons are illustrated in Fig. 4. FIG. 4: Subprocesses that contribute to trilepton (a) and 5l (b) events at hadron colliders. When Extended cascade diagrams for 3, 5, or 7 charged leptons the lightest neutralino is dominantly singlino, the trilepton process is enhanced kinematically since χ in the xmssm has the same mass as χ in the MSSM with the same parameters. The 5l events may be associated with χ 3 production (or may also be due to χ± χ l ν l). The yields an enhanced trilepton rate compared to the MSSM as χ is lighter, providing more available phase space in the decay. Further, since the second lightest neu-

28 Chargino decays occur via χ ± χ W χ l ν l in (a,b) and χ ± χ W in (c,d). Note that > 3l + χ )...8 MSSM --> 3l + χ )...8 MSSM Bf(χ χ +/-.6.4 Bf(χ 3 χ +/ Δ (GeV) (a) Δ 3 (GeV) (b).. --> 5l + χ ).. MSSM --> 7l + χ ). e-5 MSSM Bf(χ χ +/- e-5 e-6 Bf(χ 3 χ +/- e-6 e-7 e Δ (GeV) e Δ 3 (GeV) (c) (d) Decays into 3, 5, or 7 charged leptons FIG. 5: Branching ratios of neutralinos and charginos to 3l, 5l and 7l via on shell Z and W bosons vs. the neutralino mass-splitting ij = m χ m i χ where the leptons are summed over e ± and j µ ±. Neutralino decays proceed through (a) χ χ l l, (b) χ 3 χ l l, (c,d) χ 3 χ l l χ + 4l.

29 MSSM WMAP WMAP Ω χh Ω χh Mχ (GeV) Mχ (GeV) 3 WMAP WMAP Ω χh Ω χh Mχ (GeV) Mχ (GeV) 5 3 FIG. : Neutralino relic density versus the lightest neutralino mass. The relic density is constrained Relic.3 densities squarks sleptons) to be in the region > ΩDM(heavy h >.99 provided and that the model is solely responsible for the observed dark matter. The efficient annihilations through the Higgs boson pole in the MSSM, and are evident at mχ MH / 6 GeV and of the Z boson pole at mχ MZ / in the.

30 MSSM. Ω χh >.3. Ω χh >.3 e-5 Ωχh <.99.99<Ω χh <.3 e-5 Ωχh <.99.99<Ω χh <.3 e-6 EDELWEISS CDMS 5 e-6 EDELWEISS CDMS 5 (pb) σ χp SI e-7 e-8 e-9 CDMS 7 SuperCDMS 5kg (pb) σ χp SI e-7 e-8 e-9 CDMS 7 SuperCDMS 5kg e- WARP 4 kg e- WARP 4 kg e- e- e M χ (GeV) (a) e M χ (GeV) (b). Ω χh >.3. Ω χh >.3 e-5 Ωχh <.99.99<Ω χh <.3 e-5 Ωχh <.99.99<Ω χh <.3 e-6 EDELWEISS CDMS 5 e-6 EDELWEISS CDMS 5 (pb) σ χp SI e-7 e-8 e-9 CDMS 7 SuperCDMS 5kg (pb) σ χp SI e-7 e-8 e-9 CDMS 7 SuperCDMS 5kg e- WARP 4 kg e- WARP 4 kg e- e- e M χ (GeV) (c) e M χ (GeV) (d) FIG. 8: Spin independent detection cross sections Expected SI direct detection cross-section for (a) MSSM, (b) (c) Columbia and (May (d). 7, 7) The expected sensitivities of the EDELWEISS, CDMS II (5), Paul Langacker CDMS 7, (IAS) SuperCDMS (5 kg) and WARP (.3L) experiments are shown. Over most of the neutralino mass

31 Quasi-Chiral Exotics (J. Kang, PL, B. Nelson, in progress) Often find exotic (wrt SU() U()) quarks or leptons at TeV scale Assume non-chiral wrt SM gauge group (strong constraints from precision EW, expecially on extra or mirror families) Can be chiral wrt extra U() s or other extended gauge Usually needed for U() anomaly cancellation Modify gauge unification unless in complete GUT multiplets Can also be more extreme exotics (e.g., adjoints, symmetric, fractional charge, mixed quasi-hidden) Experimental limits relatively weak

32 Examples in 7-plet of E 6 D L + D R (SU() singlets, chiral wrt U() ) ( ) ( ) E E E + E (SU() doublets, chiral wrt U() ) L R Pair produce D + D by QCD processes (smaller rate for exotic leptons) D or D decay by D u i W, D d i Z, D d i H if driven by D d mixing (not in minimal E 6 ; FCNC) m D > GeV (future: TeV) D quark jets if driven by diquark operator ūū D, or quark jet + lepton for leptoquark operator lq D (still have stable LSP) May be stable at renormalizable level due to accidental symmetry (e.g., from extended gauge group) hadronizes and escapes or stops in detector (Quasi-stable from HDO τ < / yr)

33 Scalar and Fermion Mass Splittings i m D/ m D i for M D = m D/ = 3 GeV

34 i m D/ m D i for M D = 4 GeV

35 Leptoquark and Diquark Couplings Consider single family of exotic D + D c and SM singlet S: W = h s SH u H d }{{} µ eff =h s S + h D SDD c }{{} M D =h D S + W LQ + W DQ }{{} only one (proton decay) W LQ = λ 6 Du c e c +λ 7 D c QL W DQ = λ 9 DQQ+λ D c u c d c SINDRUM II: σ(µ T i e T i ) σ(µ T i capture) < λ 6,7 < 3 4 ( md GeV ) K L K S mass difference: λ 9, <.4 Still have unbroken R p, stable LSP ( max(mũi ),m D ) / GeV

36 Production Cross Sections

37

38 Decays Mixing (e.g., if ν or ν c have vev) D / dz, dh, uw No mixing: diquark induced (or leptoquark analog) D q c q c, D / χ, D / g }{{} if allowed D / D χ, D g, q c q c (if allowed) D / (D χ, q c q c ) u c d c χ (otherwise)

39 Quasi-stable (e.g., U() N model) W = M (D c QH d S, D c QQu c, D c QLν c ) D / dz, dh, uw, dhs, q q q, q l l, l q l Strong (but model dependent) constraints from nucleosynthesis (e.g., n p affects 4 He) LHC: hadron and muon calorimeters; delayed decays

40 Nucleosynthesis Bounds for Quasi-Stable W = M (Dc QH d S, D c QQu c, D c QLν c ) (one family) excluded region: Kawasaki, Kohri and Moroi, Phys. Rev., D7 (5)

41 Conclusions Combination of theoretical ideas and new experimental facilities may allow testable theory to Planck scale From the bottom up: there may be more at TeV scale than (minimal SUGRA) MSSM (e.g., Z, extended Higgs/neutralino, quasichiral exotics) From the top down: there may be more at TeV scale than (minimal SUGRA) MSSM Dynamical µ term leads to very rich Higgs/neutralino physics at colliders and for cosmology Consider alternatives to the minimal seesaw