E 6 GUT Models and FCNC Processes
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Transcript of E 6 GUT Models and FCNC Processes
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EE66 GUT Models GUT Modelsandand
FCNC Processes FCNC Processes Kazuki SakuraiKazuki Sakurai
with S-G.Kim, N.Maekawa, A.Matsuzaki, T.Yoshikawawith S-G.Kim, N.Maekawa, A.Matsuzaki, T.Yoshikawa
(Nagoya Univ.)(Nagoya Univ.)
2007/8/4 SI07@Fujiyoshida
PlanPlanI. Introduction I. Introduction
II. EII. E66 GUT and Horizontal Symmetry GUT and Horizontal Symmetry
III. Search for EIII. Search for E66×Horizontal GUT ×Horizontal GUT
-- Lepton Flavor Violation -- Lepton Flavor Violation
-- CPA in rare B meson decay -- CPA in rare B meson decay
IV. Summary IV. Summary
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Supersymmetry is promising candidates of New Physics.Supersymmetry is promising candidates of New Physics. However thHowever they have some phenomenological problems.ey have some phenomenological problems.
Problems in MSSMProblems in MSSM
Universal sfermion massesUniversal sfermion masses
Large SUSY breaking scaleLarge SUSY breaking scale
Not large stop massesNot large stop masses
SUSY Flavor ProblemSUSY Flavor ProblemGenerally, SUSY breaking terms brake flavor symmetry. They generate too large FCNCs.
Little Hierarchy ProblemLittle Hierarchy Problem
Up-type Higgs mass get a large quantum correction which proportional to stop mass.
Suppressed SUSY CP phasesSuppressed SUSY CP phases
Large SUSY breaking scaleLarge SUSY breaking scale
SUSY CP ProblemSUSY CP ProblemGenerally, couplings in SUSY breaking terms are complex. Such couplings violate CP and induce too large EDMs.
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Horizontal SymmetryHorizontal SymmetryFlavor symmetry is natural idea, in order to realize the universal sfermion mauniversal sfermion masses.sses.
First two generations are identified as SU(2)H (or U(2)H) doublet. Third generation is singlet.
:singlet :doublet
If SUSY breaking mediation scale is higher than SU(2)H breaking scale, SUSY breaking terms should respect the SU(2)H symmetry.
Universality in first two generations is realized due to SU(2)H!!
SU(2)H invariance forbid Yukawa interactions in tree level except for top Yukawa.
in SO(10), E6
SU(2)H
SU(2)H breaking effect generate first two generation Yukawa couplings through higher dimensional terms.
Horizontal sym. can explain smallness of Yukawa couplings!!
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Horizontal Symmetry Horizontal Symmetry However,However, if is lepton doublet…
In mass eigenstate basis of fermion,
Neutrino oscillation suggest is large mixing. Therefore large off-diagonal entries arise after this unitary transformation.
Such large off-diagonal entries induce too large Lepton Flavor Violation.
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EE66 Unification UnificationE6 GUT models are interesting, because…
-- all one generation quarks leptons are unified into 2727.
decouple
-- realistic Yukawa hierarchies are obtained.
Low energy three 55(Dc L) of SU(5) come from
only first two generation of 2727 not 272733.
Guisey-Ramond-Sikivie,Aichiman-Stech, Shafi,Barbieri-Nanopoulos,Bando-Kugo,…
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EE66 Unification UnificationE6 GUT models are interesting, because…
-- all one generation quarks leptons are unified into 2727.
decouple
-- realistic Yukawa hierarchies are obtained.
Low energy three 55(Dc L) of SU(5) come from
only first two generation of 2727 not 272733.
up sector:
Guisey-Ramond-Sikivie,Aichiman-Stech, Shafi,Barbieri-Nanopoulos,Bando-Kugo,…
Cabibbo angle
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EE66 Unification UnificationE6 GUT models are interesting, because…
-- all one generation quarks leptons are unified into 2727.
decouple
-- realistic Yukawa hierarchies are obtained.
Low energy three 55(Dc L) of SU(5) come from
only first two generation of 27 27 not 272733.
up sector:
down &charged lepton:
Guisey-Ramond-Sikivie,Aichiman-Stech, Shafi,Barbieri-Nanopoulos,Bando-Kugo,…
Cabibbo angle
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EE66 Unification UnificationE6 GUT models are interesting, because…
-- all one generation quarks leptons are unified into 2727.
decouple
-- realistic Yukawa hierarchies are obtained.
Low energy three 55(Dc L) of SU(5) come from
only first two generation of 27 27 not 272733.
up sector:
down &charged lepton:
neutrino sector:
Guisey-Ramond-Sikivie,Aichiman-Stech, Shafi,Barbieri-Nanopoulos,Bando-Kugo,…
Cabibbo angle
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Horizontal Symmetry on EHorizontal Symmetry on E66N.Maekawa. 02, N.Maekawa, T.Yamashita 04
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Horizontal Symmetry on EHorizontal Symmetry on E66
Since contain lepton doubletlepton doublet, Neutrino oscillation suggest is large mixing.
No LFV problem due to full universality in !!
N.Maekawa. 02, N.Maekawa, T.Yamashita 04
In above sfermion masses, we can take large SUSY breaking scale with keeping stop masses around weak scale, because correspond to stop masses.
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SUSY and GUT are promising candidate of New Physics.SUSY and GUT are promising candidate of New Physics. However However they have some phenomenological problems.they have some phenomenological problems.
Problems in MSSMProblems in MSSM
Universal sfermion massesUniversal sfermion masses
Large SUSY breaking scaleLarge SUSY breaking scale
Not large stop massesNot large stop masses
SUSY Flavor ProblemSUSY Flavor ProblemSUSY breaking terms brake flavor symmetry generally. They generate too large FCNCs.
Little Hierarchy ProblemLittle Hierarchy Problem
Up-type Higgs mass get a large quantum correction which proportional to stop mass.
Suppressed SUSY CP phasesSuppressed SUSY CP phases
Large SUSY breaking scaleLarge SUSY breaking scale
SUSY CP ProblemSUSY CP ProblemSUSY breaking terms have complex coupling. Such couplings violate CP and induce too large CPV observables (EDMs,...).
Some problems in MSSM can be solved in E6×Horizontal GUT models!!
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Search for ESearch for E66×Horizontal GUT×Horizontal GUTNext question is,how can we confirm this model experimentally?
[ Strategy ]
It is expected that FCNC processes become large through the sfermions in 10 of SU(5).
Lepton Flavor Violation, CP asymmetries in B meson decay
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Lepton Flavor ViolationLepton Flavor Violation
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Lepton Flavor Violation Lepton Flavor Violation Lepton Flavor Violations (LFVs) are good process for search the New Physics, because LFV processes are forbidden in Standard Model.
In E6 models, LFV processes take place with picking up the off-diagonal entries respectively.
We can get parameter independent prediction,
Since 10 of SU(5) contain not , final state lepton have right-hright-handed chiralityanded chirality.. We can check this by measuring angular distribution of final state lepton.
Left-handed
Right-handed
spin
spin
e
e+
++
+
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Can we discover the LFVs Can we discover the LFVs at future experim at future experim
ents?ents?
(exp. bound)
8105.4
super-KEKB
11100.1 (exp. bound)
MEG experiment
may be discovered in KEKB or super-KEKB, If < 250GeV.
may be discovered in MEG, If < 300GeV.
S.-G.Kim, N.Maekawa, A.Matsuzaki, K.S, T,Yoshikawa ‘06
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CP asymmetries CP asymmetries in rare B meson decayin rare B meson decay
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CP asym. of BCP asym. of BφKφKss, B, Bη’Kη’KssTime dependent CP asymmetry of BφK, Bη’K are composed of two part, B-Bbar mixing part and direct decay part.
In SM, CP violation is contained in only B-Bbar mixing part through a KM phase.
gluino:
chargino:
0.68 (SM prediction)
SM predictions may deviate from experiments.
SUSY CP phase can contribute in direct decay parts. So, current deviations may be explained.
Gluino and Charginoare always interfere with same sign!
in this model.
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Numerical ResultsNumerical Results (preliminary)
tota
l
tota
l
chargino chargino
gluino(C8)
gluino(C8)gluino(C3-6)gluino(C3-6)
Deviations from SM can be large(~±0.15)!!
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Numerical ResultsNumerical Results (preliminary)
Scanning in SUSY CP phase
E6×Horizontal GUT models suggest that current deviations can be true!
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SummarySummaryE6×Horizontal GUT models can solve some problems in MSSM.
Final state lepton have right-handed chirality.
There are large parameter region in which LFV decays can be discovered in near future experiments.
KEKB or super-KEKB < 250 GeV
MEG experiment < 300 GeV
We analyze the Lepton Flavor Violations.
Parameter independent predictions
We analyze the CP asymmetry in rare B decays.
Deviations from SM of Time Dependent CP Asymmetry of Bdφ,η’ Ks:
Gluino and chargino always interfere with same sign, which makes CPA large enough to be able to detect in future experiments.
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Numerical ResultsNumerical Results (preliminary)
tota
l
tota
l
chargino chargino
gluino(C8)
gluino(C8)gluino(C3-6)gluino(C3-6)
decoupling
gluino(C8):
Deviations from SM can be large(~±0.15) and non decoupling for m !!
chargino:
non decoupling
finite
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NeutrinosNeutrinosRight-handed neutrino masses:Right-handed neutrino masses:
Seasaw mechanism:Seasaw mechanism:
decoupleMass scale:Mass scale:
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Lepton Flavor Violation Lepton Flavor Violation Lepton Flavor Violations (LFVs) are good process for search the New Physics, because LFV processes are forbidden in Standard Model.
In E6 models, LFV processes take place through the off-diagonal entries respectively.
We can get parameter independent prediction,
Since 10 of SU(5) contain not , final state lepton have right-handed right-handed chiralitychirality.. We can check this by measuring angular distribution of final state lepton.
Left-handed
Right-handed
spin
spin
e
e+
++
+
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Non Decoupling FeaturesNon Decoupling Features
If we raise overall SUSY scale m …
Propagator suppression increase, but also mass difference increase.
As a result, both transition rate remain finite, and don’t decouple!
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Characteristic Feature of Characteristic Feature of Decay Decay
Chirality flip take place at first vertex and intermediate state is right-handed. initial lepton == left-handed, final lepton == right-handed
Chirality flip is required from operator form.
ie jep
ppq
p
Right-handed
Left-handed
spin
spin
We can check this feature experimentally by measuring the angular distribution of final state lepton for spin direction of initial lepton.
e
e
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Numerical ResultsNumerical Results
Non decoupling features
In > 800 GeV region, the Branching ratios are independent of .
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Time Dependent CP Time Dependent CP AsymmetryAsymmetry
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BBdd φK φKss, η’K, η’Kss
SM (>>SUSY 31 transition.) Loop = SM + NP
(SUSY)
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OPEOPE
…
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Gluino-Chargino InterferenceGluino-Chargino InterferenceGluino: Chargino:
=
Chargino contribution have a same CP phase as gluino’s one. Strong interference (additive or negative)
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Numerical ResultsNumerical Results(preliminary)
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bbsγ constrantsγ constrant
Charged Higgs
Chargino with CKM
Chargino with θSUSY
b sγ constraint requires large SUSY phase.
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EE66 GUT GUTSymmetry Breaking:
Fields and Rep.:
Guisey-Ramond-Sikivie,Aichiman-Stech, Shafi,Barbieri-Nanopoulos,Bando-Kugo,…
generation
MSSM: E6 GUT:
at low energy:
decoupledecouple
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E6 × R parity invariant interactions :
SM interactions
assumption
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EE66 GUT GUT M.Bando, N.Maekawa. 01N.Maekawa, T. Yamashita 02
assumption
up sector
downcharged lepton
Good :for up sector due to the assumption
Bad :for down and charged lepton sectors
Desired Yukawa structures are obtained in E6 GUT model !!
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Up quark mass ?Up quark mass ?
eigenvalues
Experiments:Models:
Disagreement !?
Naïve order of up quark mass is larger than the experimental value about 10.
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FCNC induced EDMFCNC induced EDM
finite
Non decoupling !Non decoupling !
Im
Exp. Bounds require < 10-2 .
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1 0 1 2 3
1.5
1
0.5
0
0.5
1
1.5
2
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Gauge invariant InteractionsGauge invariant Interactions
SU(5) invariant Yukawa interactions :
SU(5) GUT relations :
at GUT scale (1016GeV)
Not BadNot Bad
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SO(10) GUTSO(10) GUT
: SO(10) spinor : SO(10) vector
SU(5) representations:
SO(10) invariant interaction :
SO(10) GUT relation :
: at GUT scale
Grand Unified Theories unify not only the forces but also matters and interactions !!