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Obmedzenia MSSM z SO(10) zjednotenej teórie a implikácia pre kolajdre

Obmedzenia MSSM z SO(10) zjednotenej teórie a implikácia pre kolajdre. Tomáš Blažek Univerzita Komenského, Bratislava. SK-CZ Atlas workshop, Košice, 5. marec 2009. Contents. Why SO(10) Main Experimental Constraints and Their Effects

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Obmedzenia MSSM z SO(10) zjednotenej teórie a implikácia pre kolajdre

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  1. Obmedzenia MSSM z SO(10) zjednotenej teórie a implikácia pre kolajdre Tomáš Blažek Univerzita Komenského, Bratislava SK-CZ Atlas workshop, Košice, 5. marec 2009

  2. Contents • Why SO(10) • Main Experimental Constraints and Their Effects • Examples of Best Fits from the Global Top-Down Analysis • Implications for SUSY searches

  3. Well-Known SO(10) Virtues • SM fermionic multiplets of one family (15 Weyl fermions) × 3 colours + fit nicely into the 16 of SO(10): • the 16 is a chiral rep -> mass term M 1616 is not allowed by S0(10) gauge symmetry-> the 16 is massless if SO(10) is exact • anomaly canceled automatically, since SO(10) is anomaly free, unlike SU(3)c×SU(2)L×U(1)Y or SU(5) • the extra 16th state right-handed neutrino quantum numbers, not protected against geting massive below MGUT setting stage for the L number violation and see-saw mechanism after EWSB • Similarly the two Higgs doublets fit into a massless 10 • Gauge couplings unify

  4. Trojuholníková anomália kalibračná symetria SM je pokazená (narušená) procesmi, ktoré obsahujú diagram Vρb Vρb + Vμa Vμa Vμa = Bμ, Wμa, aleboGμa Vσc Vσc Symetriu možno zachrániť iba ak ∑ Tr{ TaTbTc} + Tr{ TaTcTb} = 0 fermióny Príklad: nech sú všetky tri bozóny hypernábojové B-éčka. Potom Ta = yf1. Tieto komutujú, ľavá strana je preto ∑ 2(yf)3 fermióny Hodnoty yf =2(Q-T3) pre ec,L,dc,uc,Q sú 2,-1,2/3,-4/3,1/3. Suma z (yf)3je 23+2(-1)3+3(2/3)3+3(-4/3)3+2·3(1/3)3 = 0

  5. Veľké zjednotenie v Minimálnom supersymetrickom štandardnom modeli: zbiehanie väzbových konštánt (nábojov) pri veľkej prenesenej hybnosti Tieto hodnotyα1, α2 a α3≡αs sú vypočítané z experimentálne nameraných veličín pri energií 100 GeV αS V poruchovej teórii vieme z kvantových slučkových procesov vypočítať sklon kriviekα1, α2 a α3. Sklon závisí od častíc v slučkách: ak vynecháme SUSY častice, krivky sa nepretnú. αS(MZ)=0.118 α2(MZ)=0.036 α2 α1 α1(MZ)=0.010 α |q| q = prenesená hybnosť α (|q|→0) = 1/137 = 0.0073 α(MZ) = 1/128 = 0.0078 100 GeV 1016 GeV

  6. Well-Known SO(10) Virtues cont’d • The 16310163 operator gives order one yukawa coupling: • get a heavy top quark • EW symmetry broken radiatively (for universal scalar masses) • prediction • yt ≈ yb ≈ ytau ≈ yνtau • includes successful idea of b-tau unification • The see-saw mechanism then predicts about the right hierarchy between the charged fermions and much lighter neutrinos • ... and there is more that is less well-known and is coming in this talk

  7. SO(10) Troubles • proton decaying too rarely (unobserved, in fact) ... dim 5 operator due to the coloured triplet higgs vs. the sign of the MGUT correction to αs • The 16310163 operator gives order one yukawa coupling: • Prediction • yt ≈ yb • implies large amount of fine tuning at EWSB scale: must get vd≈3GeV, as mt(MZ)/mb(MZ)≈50, • i.e., need large tanβ • Moreover, scalar higgs masses run very steep – Fig. • Since mc/mt« ms/mb, mmu/mtau and also • mu/mc« md/ms, • different higher-dimensional operators generate fermion masses of the two lighter generations • UV completion ?

  8. Running MSSM mass parameters

  9. SO(10) studies • Approach 1: study a particular model, which can be more or less complete, generating higher dimensional operators, and filling in the 3×3 yukawa matrices at MGUT by reading out the individual entries from the Frogatt-Nielsen diagrams OR • Approach 2: be less specific and study „SO(10)-like models“ in an MSSM analysis below MGUT which just takes into account the large yukawa couplings of the third generation

  10. SO(10) studies Approach 1: Implemented in • and a number of follow-up papers. • Strategy: Do pure top-down global analysis evaluating χ2from the comparison with the available low energy data. See Table. • Important details: • Include GUT threshold correction to αs • Gravity mediated SUSY breaking with non-universal scalar higgs masses • Face fine tuning with an embedded minimisation procedure, separately minimising χ2using the non-universal higgs masses for each set of the GUT parameters

  11. Table of Low Energy Observables

  12. Table of Low Energy Observables MSSM analysis only

  13. BR(b sγ) Constraint Effective Hamiltonian: ~ where η= αs(MZ) / αs(μ) Contributions to C7(MZ): chargino diagram enhanced by tanβ picks up the sign of the μ parameter SUSY CKM contrib non-negligible C7 or T.B. + S.Raby: b --> s gamma with large tan .BETA. in a MSSM analysis constrained by a realistic SO(10) model Phys Rev D, 59 (1999) 095002

  14. mb(mb) Constraint Large SUSY Threshold Contributions to mb(MZ): • both diagrams enhanced by tanβ and proportional to μ • must be of opposite signs: need negative At • still potentially too large: pushes μ to low values ... get low mass higgsino-like charginos and neutralinos • for the same reason the global analysis best fits prefer heavy gluino. That means rather large M1/2 which through the RGEs feeds into large scalar masses.

  15. Constraint from the muon anomalous magn moment SUSY Contributions to aμ: • no freedom to choose the sign: could have gone the opposite way than the BNL measurement, but it has not • the low value of μ and heavy scalar masses tend to prefer lesser contribution than what is measured in the e+e- exp. • If the result stays, it could be a hint for a non-universal SUSY breaking mechanism. • both diagrams enhanced by tanβ and proportional to μ, chargino contribution typically greater T.B. + S.F.King : Muon anomalous magnetic moment and .TAU.-->.MU.GAMMA. in a realistic string-inspired model of neutrino masses Phys. Lett B. 518, (2001), 109

  16. Constraint from non-observation of Bs to μ+μ- There are SUSY contributions to this decay amplitude that are enhanced by (tanβ)3. These contributions are mediated by the pseudoscalar higgs exchange -> sensitivity to its mass: • need pseudoscalar higgs mass typically greater than 300 GeV T.B., S.F.King, J.Parry: Implications of B_s -->.MU.+.MU.- in SO(10)-like models Physics Letters B. - Vol. 589, (2004), 39

  17. Examples of Global Analysis Best Fits T.B., R.Dermíšek, S.Raby: Predictions for Higgs and supersymmetry spectra from SO(10)Yukawa unification with .MU. > 0 Physical Review Letters. - Vol. 88, (2002), 111804

  18. Examples of Global Analysis Best Fits

  19. Examples of Global Analysis Best Fits

  20. Another Example of Global Analysis Best Fits

  21. Implications from the SO(10)-like models best fits • the lightest CP even higgs very close to the current limit mh ≈ 115-120 GeV • the rest of the higgs spectrum above ≈ 250-300 GeV • light higgsino-like charginos and neutralinos close to 100 GeV, the LSP is most of the times a higgsino-like neutralino • possibly a light stop and stau (and maybe sbottom) due to the large left-right splittings • the rest of the MSSM sparticle spectrum at/above the TeV scale • CDM is formed by a mixture of bino/higgsino-like neutralino LSP and should be observed in the near future, or the LSP is higgsino-like LSP that annihilates too rapidly to form the dominant CDM component

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