Models and Non Standard Model
with Neutrinos
Pilar Hernández
University of Valencia/IFIC
SM + massive ns
Fogli et al 2012 (after T2K,
Double-CHOOZ, Daya Bay, RENO)
3n mixing:
Standard 3n scenario
The flavour observables:
Masses
m12 < m22, m32
Angles
CP-phases
q12,q23,q13
d, a1, a2
Good prospects for CP volation
Coloma, Donini, Fernandez-Martinez,PH arXiv:1203.5651
New dofs puzzle
Neutrinos are massive -> there must be new dofs in the SM
New dofs puzzle
Neutrinos are massive -> there must be new dofs in the SM
Weinberg
SM
nSM
?
The good nSM
• Explanation for the neutrino-charged lepton
hierarchy
The n flavour puzzle I
Why are neutrino masses so light ?
The good nSM
• Explanation for the neutrino-charged lepton
hierarchy
• Explain the pattern of mixing
CKM
The n flavour puzzle II
VCKM =
PDG 2007
PMNS
Gonzalez-Garcia, Maltoni
Differences are striking!
The good nSM
• Explanation for the neutrino-charged lepton
hierarchy
• Explain the pattern of mixing
• Explain other open problems: DM, matterantimatter, oscillation anomalies, cosmology
anomalies…
Massive Neutrinos & fundamental questions
in Particle Physics and Cosmology
Structure of the vacuum ?
DE ?
DM ?
Baryons ?
Flavour Puzzle: twice as many pieces ?
Growth of structure
Outlier I: LSND anomaly
LSND vs KARMEN
Appearance signal with very different
-
Not yet disproved at an acceptable level of confidence…
Pinning down the New physics scale
Hierarchy problem or SUSY ?
meV
eV
keV
MeV
GeV
TeV
Leptogenesis
SUSY GUTs
Pinning down the New physics scale
bb0n
LFV processes,
Precision tests, LHC
Neutrino osc.
meV
eV
CMB, LSS
keV
MeV
GeV
Baryogenesis
Nucleosynthesis
Hierarchy problem or SUSY ?
TeV
Leptogenesis
SUSY GUTs
The good nSM
• Explanation for the neutrino-charged lepton
hierarchy
• Explain the pattern of mixing
• Explain other open problems: DM, matterantimatter, oscillation anomalies, cosmology
anomalies…
• Do so, in a predictable and testable
way !
No signal of SUSY/solution-of-hierarchyproblem at the LHC (yet)…
Occam’s razor
Pinning down the New physics scale
2) LHC reach
3) LSND reach
1) Decoupling physics
Warm DM ?
Hierarchy ?
meV
eV
keV
LSND, reactor anomalies?
Extra radiation ?
MeV
GeV
TeV
Matter/antimatter asymmetry ?
Ruchayskiy’s talk
GUT ?
Effective Theories of Neutrino Masses
(model-independent)
If L >> v low-energy effects should be well described by an effective field
theory:
Weinberg; Buchmuller, Wyler;…
Oid built from SM fields satisfying the gauge symmetries
Only one with d=5: Weinberg’s operator or neutrino masses !
Generically d=6 operators: rich phenomenology
d=6 phenomenology
Long list of flavoured-operators
• rare lepton decays: m -> e g
• Z, W decays
• rho parameter
• W mass, …
• violations of universality, unitarity,…
But…
la -> lb g
MEG
If just neutrino masses:
If also d=6 operators @one loop
Could d=6 be stronger ?
Yes if two independent scales in d=5, d=6 from a symmetry principle: lepton number
Cirigliano et al 05, Kersten,Smirnov 07 ; Abada et al 07
Ld=5~LLN
>> Ld=6 ~ LLFV ~ TeV
Origin of lepton/quark flavour violation linked to the LEW
Lepton number breaking scale higher and responsible
for the gap between n and remaining fermions
Are d=6 flavour structures related to neutrino masses ?
Minimal Flavour Violation
Chivukula, Georgi; Buras et al.;D’Ambrosio et al; Cirigliano et al; Davidson et al,
Gavela, et al
(cd=5)ab ~ (cd=6)ab~ mn
All flavour violating effects determined by neutrino masses and mixings
Unfortunately not the case for most popular models of neutrino mass
(ex. Type I seesaw)
BSM and Neutrino Masses
(Up->Down approach)
?
New physics scale
Type I see-saw: interchange a heavy singlet fermion
Minkowski; Gell-Mann, Ramond Slansky; Yanagida, Glashow…
New physics scale
Type II see-saw: interchange a heavy triplet scalar
Konetschny, Kummer; Cheng, Li; Lazarides, Shafi, Wetterich …
New physics scale
Type III see-saw: interchange a heavy triplet fermion
Foot et al; Ma; Bajc, Senjanovic…
New physics scale
Also from loops !
Zee-Babu
Systematic exploration of 1-loop generated Weinberg interaction
Bonnet et al 2012
Effective see-saw theories
Also d=6 operators
Type I
Non-unitarity in
mixing !
Type III
Type II
Gavela, Broncano, Jenkins; Abada, et al
Type I Seesaw
Most general (renormalizable) Lagrangian compatible with SM
gauge symmetries:
Y: 3 x nR
mn
MN: nRx nR
ms
One scale see-saw models
Ye
Type I or III + (approx) Lepton number
Wyler, Wolfenstein; Mohapatra, Valle;
Branco, Grimus, Lavoura, Malinsky, Romao,…
nR
Inverse Seesaw
Direct Seesaw
L= +1
mn
-1
+1
mn
M2N/m
v MN/m
Y unsuppressed:
-> LFV effects at LHC, large m-> e g, etc
-> heavier spectrum MN, Yv
Kersten,Smirnov 07; Abada et al 07; Gavela,et al 09
Minimal Flavour type I seesaw model
Gavela, Hambye, Hernandez, PH 09
Only two extra Weyl fermions + SM
Y, Y’ complex vectors, L, m, m numbers
Minimal type I seesaw model
Neutrino masses & mixings determine Y up to a global normalization
(and Majorana phase)
Normal hierarchy
Inverted hierarchy
Also Raidal, Strumia, Turzynski 2004; Ibarra et al 2010
Complementarity of CLFV and neutrino oscillations
NH
IH
Gavela, Hambye, Hernandez, PH 09
CLFV within reach
Dinh, Ibarra, Molinaro, Petcov 2012
LLFV ~ TeV: direct searches at LHC ?
Keung, Senjanovic;…
Generically it is needed
• Gauge interactions of extra fields for large enough production
(ex. type II and type III)
• Low enough masses for kinematical constraints
Type II: Han et al;Garayoa, Schwetz; Kadastik,et al ; Akeroyd, et al;
Fileviez et al, del Aguila et al
Type III: Franceschini et al; Arhrib et al; Eboli et al…
Minimal Flavour See-saw III at LHC
Eboli, Gonzalez-Fraile, Gonzalez-Garcia 2011
CMS-PAS-HIG-12-005
Type II seesaw
LSND anomaly
In order to accommodate a new
• Need at least four (ns ≥1) distinct eigenstates
• Apparently CP violating effect needed (signal LSND/MB anti-n not MB n)
ns ≥ 2
• Tension appearance (signal) and disappearance (no signal) ?
• Tension with cosmology ?
Outlier II: reactor anomaly
Re-calculation of reactor fluxes:
old fluxes underestimated by 3%:
Mueller et al, ArXiv: 1101.2663
Outlier III: Cosmology
Hamann et al, ArXiv: 1006.5276
Sterile species favoured by LSS and CMB
Nucleosynthesis:
Izotov, Thuan
3+2 neutrino mixing model
Parametrized in terms of a general unitary 5x5 mixing matrix
(9 angles, >6 phases physical)
Kopp, Maltoni, Schwetz (KMS) arXiv:1103.4570
Giunti, Laveder, (GL) arXiv:1107.1452
Significant improvement over 3n scenario, but tension appearance/disappearance
remains
Pheno 3+ns mixing models ?
Assumes a general mass matrix for 3+ns neutrinos: what is that model ?
3x3
3xns
Pheno 3+ns mixing models ?
Assumes a general mass matrix for 3+ns neutrinos:
Gauge invariance
Effective theory: MLL parametrizes our ignorance about the
underlying dynamics (eg. a model with nR > ns, where
the heavier states are integrated out)
Type I see-saw models
Light sterile states!
De Gouvea, hep-ph/0501039
De Gouvea, J. Jenkins, Vasudevan hep-ph/0608147
Minimal models
Most general (renormalizable) Lagrangian compatible with SM
gauge symmetries:
3+2 minimal much more predictive than 3+2 pheno
Donini, PH, Lopez-Pavon, Maltoni 2011; De Gouvea et al 2011;
Heavy-Light Mixings
Heavy-light mixings are predicted up to a complex angle z45 and two
CP phases !
Normal Hierarchy
Suppressed in
Inverse Hierarchy
and
Suppressed only in
3+2 MM vs 3+2 PM vs 3n
Donini, PH, Lopez-Pavon, Maltoni, Schwetz ‘12
Heavy-Light Mixings
e
m
t
Large tau mixings to heavy states
Constraint on
Constraint on
BUT….
Significant improvement over 3n scenario, but large tension
appearance/disappearance in m sector remains (MINOS CC high energy)
Tension with cosmology that favours extra lighter states
New info from T2K ND ?
We are still lacking an independent confirmation of LSND at the
same level of confidence…
New experimental programme ahead by SBL: Mauri’s Talk
A hierarchy ?
?
Conclusions
•A espectacular experimental progress in neutrino physics has opened
a whole new flavour sector in the SM
•But neutrino masses require new dofs and most probably a new energy scale
•No hint of the scale…
Dirac n
0
SUSY-GUTs
TeV
Rich phenomenology: must be
explored systematically !
1015GeV
n’s have the highest score at bringing surprises…
….ask these people
BACKUPS
Flavour Symmetries ?
A lot of work has been devoted to justify the tri-bimaximal mixing features of U:
But data is getting further away from TB…
Incorporating deviations very model dependent…
Or Anarchy ?
Doing just fine…
De Gouvea, Murayama 2012
Dark portals
Schabinger, Wells 05
Patt Wilczek 06
Only two gauge and Lorentz invariant combinations in SM with
d <4
Bosonic
Fermionic
Any hidden sector singlet under SM gauge group can
couple to the dark portals
MiniBOONE- n
Neutrino run
200 MeV ≤ En ≤ 3 GeV
-
Low energy excess…but not expected if LSND right
–
MiniBOONE-n
Anti-Neutrino run
Compatible with LSND !
-
475-1250MeV
1250-3000MeV
Excess
20.9 ±13.9
3.8±5.8
LSND-best fit
22
3.5
Leptogenesis
Most interesting and robust implication with these models
Works out in
Type I Fukuyita, Yanagida,…
Type II Ma,Sarkar, Hambye
Type III Hambye, Li, Papucci, Notari, Strumia
Recent progress:
flavoured leptogenesis -> follow dynamics of Le, Lm, Lt
Abada, et al; Nardi, et al
Relaxing bound on light neutrino mass
Leptogenesis stew
L violation
But neutrino mass matrix does not provide the exact recipe!
Type II with LLFV << LLN
If m=0 -> exact L
LLN = MD2/m
LLFV = MD
LFV could be measurable from d=6 operators and fully correlated with
neutrino oscillations
Spectacular effects at LHC also fully correlated with neutrino oscillations
m-> e g
Chakrabortty, Ghosh, Rodejohann
See-saw II: Pair-production of charged triplet scalars
pp-> H++ H-- -> l+l+l-lFlavour structure one-to-one to mn ! BR(H++ -> la+lb+ ) ~ |Mab|2
Keung, Senjanovic;…
Han et al;Garayoa, Schwetz; Kadastik,et al ; Akeroyd, et al; Fileviez et al