1. Phenomenology of Three-Loop Neutrino Masses Models
Amine AHRICHE
Department of Physics, University of Jijel,
Algeria
NTU-Taipei, December 21st 2015

2. Outlines The Models: Motivation & Description
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Outlines
The Models: Motivation & Description
Neutrino Mass vs Exp. Constraints
Dark Matter
EW Phase Transition
Higgs Decay channels h→ γγ and h→ γZ
Collider Signatures
Conclusion
based on A.A. & S. Nasri, JCAP 07 (2013) 035
A.A., S. Nasri & R. Soualah, Phys. Rev. D 89, (2014)
A.A., C.-S. Chen, K.L. McDonald & S. Nasri, Phys.Rev. D90, (2014)
A.A., K.L. McDonald & S. Nasri, JHEP 1410 (2014) 167
A.A., K.L. McDonald, S. Nasri & T. Toma, Phys.Lett. B746 (2015) 430
A.A., K.L. McDonald & S. Nasri, Phys.Rev. D92, (2015)

3. The Models: Motivation & Description
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
The Models: Motivation & Description
The SM is very succesful, but ... ν ‘masses, gauge unification, hierarchy pb, BAU, DM, DE ..
Many extensions: gauge symmetry, particle content, space-time or introducing exotic ideas (SUSY, LH, UnParticle..)
A small ν ‘masses: Seesaw mechanism ... or Radiatively ... Zee, Babu-Zee ... etc
Our class of models is a simple (& economical) SM extension: SM + a charged singlet scalar + a scalar N-plet + 3 generations of fermion N-plets with a global Z2 symmetry. This leads to:
neutrino mass and mixing values given by the Exp;
DM candidate: relic density & direct & indirect search Exp;
Higgs mass at 125 GeV & possible deviation in h→ γ γ;
Strong first order phase transition;
Interesting signals at the colliders.

4. Different classes: Fields content: Z2: Z2: (n=2) softly broken
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Different classes:
Fields content:
Z2:
Z2: (n=2) softly broken
: (n=3) Accidental

5. Lagrangian & Neutrino mass
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Lagrangian & Neutrino mass
Singlet case (n=0): (Krauss-Nasri-Trodden) PRD67, (2003), JCAP 07 (2013) 035

6. Lagrangian & Neutrino mass
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Lagrangian & Neutrino mass
Triplet case (n=1): Phys.Rev. D90, (2014)
Inside the loops:

7. Lagrangian & Neutrino mass
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Lagrangian & Neutrino mass
5-plet case (n=2): JHEP 1410 (2014) 167
breaks Z2 : softly
Inside the loops:

8. 7-plet case (n=3): Phys.Lett. B746 (2015) 430
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
7-plet case (n=3): Phys.Lett. B746 (2015) 430
Accidental Z2
These estimated neutrino mass matrix elements have to be matched observed values
We do not know the neutrinomass hierarchy: normal or inverted? and the absolute neutrino mass (m1 ot m3) ?

9. Muon anomalous Magnetic moment
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Eg. 5-plet
LFV
Muon anomalous Magnetic moment
Exp. Bounds:
Neutrinoless ββ decay bound on

10. Space parameters: KNT (n=0) Triplet (n=1) A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Space parameters:
KNT (n=0)
Triplet (n=1)

11. Space parameters: 5-plet (n=2) 7-plet (n=3) A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Space parameters:
5-plet (n=2)
7-plet (n=3)

12. Dark Matter The observed relic density (Planck) KNT (n=0):
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Dark Matter
The observed relic density (Planck)
KNT (n=0):
The lightest E10 (RH Majorana N1) is our DM candidate
We have the self-annihilation (S2-mediated) t-channel process; and also through the co-annihilation processes
The annihilation cross section
Relic density
The co-annihilation effect can be expressed by the factor k

13. Dark Matter KNT: Interesting features: if A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Dark Matter
KNT:
Interesting features: if

14. A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Dark Matter
n>0:
The neutral component of the first generation of the fermion triplet E01
It self-annihilates through t-channel processes mediated by S and W gauge bosons: this leads to large values for DM mass
The fermion multiplet members have mass splitting of O(166 MeV), there the coanihilation effect is extremely important
The co-annihilation processes should be considered
For we have:

15. Dark Matter Triplet: Direct detection:
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Dark Matter
Triplet:
Direct detection:
The direct detection bounds (especially from XE100 or LUX) are weaker for large DM mass values

16. Dark Matter 5-plet (n=2):
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Dark Matter
5-plet (n=2):
If λ=0, DM is stable and slelf-annihilates similar to the triplet case.
But if λ<<1, it decays like
This leads to DM longlivety

17. Dark Matter 5-plet: Direct detection:
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Dark Matter
5-plet:
Direct detection:
The direct detection bounds (especially from XE100 or LUX) are weaker for large DM mass values

18. The EW Phase Transition
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
The EW Phase Transition
In 1967, Sakharov criteria:
In the SM (KRS):
B violation
C & CP violation
Out-of-equilibrium
B+L anomaly
CKM matrix
Strong first order Phase transition
B,CP
/ /
SM: Mh<45 GeV!!!

19. The EW Phase Transition
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
The EW Phase Transition
In the KNT (n=0) model, the Higgs mass is given at one-loop by
Then the Higgs mass is exactly 125 GeV for = 10􀀀1, 10􀀀2, 10 if
… it means a strong first order phase
transition is easily obtained

20. The EW Phase Transition
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
The EW Phase Transition
For n>0

21. Higgs decay channels h→ γ γ and h→ γZ
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Higgs decay channels h→ γ γ and h→ γZ
In the KNT (n=0) model, the Higgs-photon couplings get modified by the extra charged scalars. This modification is given by

22. Higgs decay channels h→ γ γ and h→ γZ
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Higgs decay channels h→ γ γ and h→ γZ
n= n=1, n=2

23. A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Collider Signatures
PRD89, (2014)
At linear collider, a (leptonic) DM particle can be checked through processes such:
(still under investigation)
where we observe as

24. A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
ILC

25. For the KNT model, we consider the process:
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
For the KNT model, we consider the process:
40 diagrams
with the background:
they are not similar!!
18 diagrams

26. We get the cross section and significance values:
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
In order to identify any signal in any experience, the significance should e be larger than 5, with
After implementing the model in LanHEP/CalcHEP, we generate different distributions and consider the selection cuts:
We get the cross section and significance values:

27. A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
In order to identify the source of missing energy source at 1 TeV, we vary the charged scalar S2 (the scalar that couples to RH neutrinos). We find
physical value

28. We get the cross section and significance values:
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Therefore, the missing energy at CM energies 250, 350 and 500 GeV is mainly LH neutrinos, while at 1 TeV, it RH Majoarana neutrinos.
Another option to enhance the significane in leptnic colliders is using polarized beams. The polarization is characterized by:
At the ILC, we have:
We get the cross section and significance values:

29. To summarize the results, we give the expected events numbers:
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
To summarize the results, we give the expected events numbers:
And when varying the luminosity, we get:
At the LHC: (in progress)

30. Thank you for your attention
A. Ahriche, U. Jijel
NTU-Taipei, December 21st 2015
Conclusion
This calss of models gives
The neutrino mass and mixing data for normal and inverted hierarhy without beeing in conflict with Exp. constraints such as LFV procesess.
Right amount of the relic density, with out being in conflict with Direct detection Exp.
A strong first order phase transition while the 125 GeV Higgs mass is easily obtained.
Possible modification in the Higgs decay channels h→ γγ & h→ γZ.
Possibly tested signals at the ILC (LHC soon published).
Thank you for your attention