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Transcript of Nobuhiro Maekawa (Nagoya Univ. KMI) TexPoint fonts used in EMF. Read the TexPoint manual before you...
Signatures of () SUSY GUT in the past and future
Nobuhiro Maekawa (Nagoya Univ. KMI)
1. GUT is attractive!2. Grand Unified Theory3. Family Symmetry4. Spontaneous CP Violation5. Predictions (FCNC and Nucleon decay)6. Impact of LHC 7. Summary
What I would like to talk today Observed SM parameters suggest GUT. Gauge couplings, quark and lepton masses and mixings GUT ( is also), effective (natural )SUSY spectrum : observed?
tan at GUT scale
Large EDM of neutron Nucleon decay modes can identify Impact of LHC(125GeV Higgs, no signal of SUSY) Large SUSY breaking scale(most of FCNC are decoupled)
Large SUSY breaking scale destablizes the weak scale
Heavy gravitino (100TeV) improves the issue.
Sfermion spectrum can be a signature of GUT.
Cosmological signature?
Thermal leptogenesis is possible in GUT, but not in GUT.
Our existence may be an indirect signature.
→Ishihara’s talk of his master thesis.
IntroductionGUT is attractive!
Grand Unified Theories
Gauge Interactions
Matter
2 Unifications
Experimental supports for both unifications
GUT is promising
Grand Unified Theories Unification of gauge interactions
quantitative evidence:
Unification of matters
qualitative evidence:
have stronger hierarchy than
hierarchies of masses and mixings lepton >>quark (in hierarchies for mixings)
ups >> downs, electrons >> neutrinos (in mass hierarchies)
Non SUSY SUSY GUT
Masses & Mixings and GUT
020
4060
80100
120140
160180
up down chargedlepton
neutrino
1st2nd3rd
- 12
-10
-8
-6
-4
-2
0
2
4
Log[M
f/G
eV
]
updowncharged leptonneutrino
u, c, t Strongest
Neutrinos Weakest e, μ , τ Middled, s, b Middle
CKM small mixings
MNS large mixings
These can be naturally realized in SU(5) GUT!!
SU(5) SUSY GUT
Quark mixings(CKM) Lepton mixing(MNS)
have stronger hierarchy than
Stronger hierarchy leads to smaller mixings
Albright-BarrSato-Yanagida…
Mass hierarchy and mixings
Stronger hierarchy leads to smaller mixings
Stronger hierarchy Smaller mixings
SU(5) SUSY GUT
Quark mixings(CKM) Lepton mixing(MNS)
have stronger hierarchy than
Stronger hierarchy leads to smaller mixings
Good agreement with masses & mixings
Grand Unified Theory
The assumption in SU(5) GUT
have stronger hierarchy than
can be derived.
Various Yukawa hierarchies can be induced from one Yukawa hierarchy in GUT.
Bando-N.M. 01N.M, T. Yamashita 02
Unification
Three of six become superheavy after the breaking
Once we fix , three light modes of six are determined.
Guisey-Ramond-Sikivie,Aichiman-Stech, Shafi,Barbieri-Nanopoulos,Bando-Kugo,…
We assume all Yukawa matrices
Milder hierarchy for
fields from become superheavy.
Light modes have smaller Yukawa
couplings and milder hierarchy than
Superheavy
• Larger mixings in lepton sector than in quark sector.• Small• Small neutrino Dirac masses Suppressed radiative LFV
unless
Bando-N.M. 01N.M, T. Yamashita 02
How to obtain various Yukawas?
SO(10) GUT relations
Large
Right-handed neutrinos
• The same hierarchy
LMA for solar neutrino problem
1st Summary unification explains why the lepton sector has larger mixings than the quark sector.(Large ) Suppressed radiative LFV
A basic Yukawa hierarchy
The other Yukawa hierarchies
Hierarchy of is stronger than that of
Three come from the first 2 generation of
Family symmetry
GUT can obtain realistic Yukawa structures so naturally that we can obtain a GUT in which all three generation quark and leptons can be unified into a single (or two) field(s) by introducing family symmetry.By breaking the family symmetry, realistic quark and lepton massesand mixings can be obtained.Peculiar sfermion mass spectrum is predicted.
Effective (Natural) SUSY type mass spectrum if SUSY flavor problem is solved with stabilization of the EW scale.
,
Can we discover the LFVat the future experiments?
11100.1 (exclude)
9100.7
(exclude)
8100.7
14100.1
MEG experiment
τ→μγ
μ→eγ Detectable if <400GeV
(super-)KEKB
Detectable, when tanβ is large and <250GeV
𝑚3=𝑚𝜏𝑅=𝑚𝑡𝑅
=𝑚𝑞3
Spontaneous CP violation
Old and new type SUSY CP problems can be solved and several bonuses
2nd Summary KM theory is naturally realized by spontaneous CP
violation in E6 GUT with family symmetry
1, Real and parameters are realized by
introducing a discrete symmetry.
2, The symmetry solves CEDM problem.
:real :complex
3, Predicted EDM induced by RGE effect is sizable.
4,
5,
6, E6 Higgs sector consistent with the above
scenario with natural realization of D-T splitting
Sizable EDM RG induces imaginary of sfermion masses GeV TeV (red, orange) TeV (blue, cyan)
Ishiduki-Kim-N.M.-Sakurai09
Nucleon decay
N.M.-Y.Muramatsu 13,14
Natural(Anomalous U(1)) GUT
Natural: All the interactions which are allowed by the symmetry are introduced with O(1) coefficients. (incl. higher dimensional int.)
We can define the model only by fixing the symmetry of the model(except O(1) coefficients) . The parameters for the definition are mainly about 10 charges for the fields.
The predictions are expected to be stable under the quantum corrections or gravity effects.
This assumption is quite natural. Infinite number of interactions can be controlled. Doublet-triplet splitting problem can be solved. Realistic quark and lepton masses and mixings. Non trivial explanation for gauge coupling unification. Anomalous U(1) gauge symmetry plays an essential role
N.M. 01N.M. T. Yamashita, 02
Nucleon decay via dim. 6 is enhanced
Unification scale becomes lower.
Proton decay via dimension 6 op.
years () years
Generic interactions
GUT model identification by nucleon decaytwo important ratios of partial decay widths to identify GUT model
to identify grand unification group
to identify Yukawa structure at GUT scale
GUT GU
T
GU
T
: dimension-6 operators which have anti electron in final state
: dimension-6 operators which have anti neutrino in final state
𝑹𝟏=¿
𝑹𝟐=
¿
model points
model points
3rd Summary Observed (or observing)
Not yet
Nucleon decay large
FCNC
Unfortunately most of FCNC processes are
decoupled when SUSY breaking scale is large.
(This is implied by observed Higgs mass.)
Impact of LHC
125 GeV Higgs
Stop mass () must be larger than 1 TeV No SUSY particle
SUSY breaking scale may be larger than we expected.
The little hierarchy problem is more serious.
FCNC problem (D term problem) is milder.
The little hierarchy problem .-Very serious problem must be solved!
N.M.-K.Takayama 14
125GeV Higgs→Heavy stop→Instability of EW scale This step is not automatic! Instability strongly depends on the explicit SUSY breaking scenario
→ 125GeV Higgs must be a hint for finding the true SUSY breaking scenario.
Little hierarchy problem GeV (LHC) TeV ()
TeV ()
Higgs mass is fixed by and at weak energy scale. Heavy stop leads to parameters tuning
TeV, , O(0.01%) tuning
TeV, , O(0.1%) tuning
TeV, , ) O(1%) tuning
Correction depends on at higher scale and .
Low mediation scale and are preferable.
Low mediation scale scenarios Gauge mediation
Mass of the messenger particles can be small.
Unfortunately it is difficult to obtain large Mirage mediation Choi-Falkowski-Nilles-Olechowski-Pokorski04,
Jeong-Kobayashi-Okumura05, Kitano-Nomura05
Due to the cancellation between anomaly mediation and RG
effects of moduli contribution, the mediation scale can be lower
effectively.
Special boundary conditions are required
Unfortunately, is not sufficiently large.
What happens if special boundary conditions are not required?
Cosmological Gravitino ProblemSUSY is still promising
Decay of gravitino produced in early universe spoils BBN. Kawasaki-Kohri-Moroi-Yotsuyanagi08
One solution
O(100TeV) gravitino
It decays before BBN!
High scale SUSY
but destabilizes the
weak scale.
Roughly TeV
What we would like to show Gravitino mass O(100) TeV
to solve the cosmological gravitino problem The other SUSY breaking parameters = O(1) TeV
for the naturalness
As in mirage mediation
The little hierarchy problem can be less severe.
O(%) tuning is realized.
Point: anomaly mediation cancels the RG contribution.
can be larger without changing
Little hierarchy problem
𝑚3/2
𝑀1 /2=60 TeV
from .We fixed
𝑚h2
2/∆𝑚𝐻𝑢
2
1, O(%) tuning is realized! (Width of 1% band is O(TeV))2, Mild dependence on (Important to obtain heavy Higgs.)
Important observation Gravitino mass O(100) TeV
to solve the cosmological gravitino problem The other SUSY breaking parameters = O(1) TeV
for the naturalness
The little hierarchy problem can be less severe.
O(%) tuning is realized.
Point: anomaly mediation cancels the RG contribution.
can be larger without changing
If O(TeV), we may observe directly the GUT signatures through the mass spectrum of the other sfermions than stops.
(ex. D-term contributions of GUT.)
Sizable D-term contribution as a signature of
N.M.-Y.Muramatsu-Y.Shigekami 14
Natural (Effective) SUSY type sfermion masses
Most of models which predict natural SUSY sferimion massesare suffering from CEDM constraints.If natural SUSY sfermion masses are observed, this scenario is implied.
Small deviation from natural SUSY sfermion masses can be a signature of GUT with family symmetry.
10: 5:
A signature from sizable D-term contributions
An important prediction
How large D-term can be allowed? We consider FCNC constraints
average down type squark mass :
:constraint from
:constraint from
When TeV
𝑥=¿
𝑦=¿
Result 1
𝑥∼𝑦∼ 0.1= D-term can be 1 TeV!
signature of SUSY GUT model in future experiments ( TeV proton collider or muon collider)
4th Summary Gravitino mass O(100) TeV
to solve the cosmological gravitino problem The other SUSY breaking parameters = O(1) TeV
for the naturalness
The little hierarchy problem can be less severe.
O(%) tuning is realized.
Point: anomaly mediation cancels the RG contribution.
can be larger without changing
If O(TeV), we may observe directly the GUT signatures through the mass spectrum of the other sfermions than stops.
(ex. D-term contributions of GUT.) Natural SUSY type sfermion masses may be directly observed. An important prediction D term can be 1 TeV! (
Summary GUT is promising Experimental supports for two unifications
GUT is interesting An assumption in GUT can be derived.
Various Yukawa hierarchies in SM can be obtained from one hierarchy.
+Family symmetry Unification of three generation quark and leptons with realistic Yukawa
SUSY flavor problem is solved (Natural SUSY type sfermion masses)
+Spontaneous CP violation Origin of KM phase can be understand
SUSY CP problem is solved. (Even CEDM constraints can be satisfied.)
Natural (anomalous U(1)) GUT The doublet-triplet splitting problem is solved under natural assumption.
Summary 125GeV Higgs must be a hint for SUSY breaking Predictions
Observed
Not yet
Nucleon decay
Sfermion mass spectrum (Natural SUSY type)
D-term contribution can be a smoking gun. Shigekami’s master thesis
Signatures for future flavor experiments?
EDM of neutron now in progress
Future works Cosmology (Inflation, DM, Baryogenesis etc)
Leptogenesis implies GUT Ishihara’s master thesis
More predictions
Issues (generic int., gauge coupling unif. etc)
Higgsino?