Transcript No Slide Title

A. Yu. Smirnov
Max-Planck Institute
for Nuclear Physics,
Heidelberg, Germany
NOW 2014
September 8– 13, 2014
There is something hidden and beyond the standards
which
strongly suppresses
badly confuses and mixes
violates the law
which is difficult to prove
and probably the first and the second
are because of the third
what is behind of
1. Smallness of neutrino mass in comparison to masses
of the charged leptons and quarks
2. “Unusual” lepton mixing pattern with two large mixing
angles (one is close to maximal) and one small which
differs from the quark mixing
3. Weaker (or no) mass hierarchy than the hierarchy of
charged leptons and quarks
In general, what is the type of mass spectrum
and mass ordering?
Nature of neutrino mass
are they of Dirac or Majorana type?
are they “hard” or “soft” (medium dependent)?
Recall that in oscillation experiments we probe
dispersion relations and not masses immediately
Effective neutrino masses in oscillation experiments in
beta decay in cosmology and bb-decay can be different
Does the nature of neutrino mass differ from the nature of
the quarks and charged lepton masses?
Usual neutrino masses can be strongly suppressed, e.g. by
the seesaw, so that ”unusual contributions” dominate
Are sterile neutrinos (if exist) relevant for the solution ?
are we asking right questions?
do we interpret the data correctly?
It is not excluded that the
correct solution (or the key to
the solution) already exists
among hundreds of approaches,
models, mechanisms, schemes,
etc.
Still something fundamental
can be missed
comparing within generation:
Special
m3
mt
Similar for other generations
if spectrum is hierarchical
~ 3 10-11
Neutrinos: no clear generation structure as
well as the correspondence light flavor –
light mass, especially if the mass hierarchy is
inverted or spectrum is quasi-degenerate
Normal?
me
-6
~
3
10
mt
m3
-6
~
3
10
me
?
10-3
gap
100
103
mass, eV
106
109
1012
The riddle is formulated as comparison with masses (and mixing) of quarks
There is no solution of the riddle of quark masses
Can we solve the neutrino mass riddle?
Do efforts make sense?
Yes, if
we still hope (as it was
before) that neutrinos
will uncover something
simple and insightful
which will allow to solve
Higgs triplet
we will try to explain the the quark mass riddle
Radiative mechanisms difference of masses and
Seesaw type III, etc. mixing of neutrinos and
quarks, and not masses
and mixing completely
neutrino mass generation
and generation of the
charged lepton and quark
masses are independent
Should mixing be included in the riddle?
Quarks
Relation between
masses and mixing
sinqC ~
md
ms
In 3 generations:
Fritzsch ansatz
Leptons
Maximal mixing - quasidegenerate mass states ?
Tri-Bi-Maximal mixing (TBM)
 no connection between
masses and mixing (at least in
the lowest order)
Realized in the residual
symmetry approach
Form invariance of the mass
matrices
Completely
related
with the only
difference that
originates from
Majorana nature
of neutrinos,
symmetries
Partially
related
Seesaw type I,
Quark-lepton
unification
GUT, seesaw type II
Largely
unrelated
Higgs triplet
Radiative
mechanisms
Seesaw type II
and III
Neutrino mass
riddle
Dark Energy
Riddle
Baryon asymmetry
in the Universe
Inflation
Dark Matter
Riddle
Dark
radiation
The riddle of new physics
common for quarks and
leptons
responsible for small quark
mixing and hierarchical
structure of the Dirac masses
additional structures in lepton
sector such as the see – saw
responsible for
smallness of neutrino mass
and large lepton mixing
These two types are different but probably
should somehow “know” about each other
Counter example, seesaw with degenerate RH neutrinos
does not work in this framework
High scale seesaw
Quark- lepton
symmetry /analogy
GUT
VEW2
mn
Looking under the lamp
Low scale seesaw,
radiative
mechanisms, RPV,
high dimensional
operators
Scale of neutrino
masses themselves
Relation to dark
energy, MAVAN?
Spurious scale?
Neutrino mass itself is the
fundamental scale of new physics
mn = - mDT 1 mD
MR
MGUT ~ 1016 GeV
MR ~
108
-
1014
GeV
1016 - 1017 GeV
q – l similarity:
for the heaviest in the presence of mixing
MGUT2
MPl
double seesaw
many heavy singlets (RH neutrinos)
…string theory
N ~ 102
In favor
Gauge coupling unification
BICEP-II ?
Leptogenesis
m D ~ m q ~ ml
Natural, minimalistic, in principles
Realizes relations:
Partial relation of the quark and neutrino properties
“Neutrinoful Universe”
T. Higaki et al,
arViv:1405.0013
Seesaw sector is responsible for inflation (scalar which breaks
B-L and gives masses of RH neutrinos), dark matter, leptogenesis
Testable?
- Proton decay
- Majorana masses
Simplest seesaw implies new physical scale
MR ~ mD2 /mn ~ 1014 GeV
<< MPl
(Another indication: unification
of gauge couplings)
nR
nL
H
F. Vissani
hep-phl9709409
H
nR
dmH2 ~
J Elias-Miro et al,
1112.3022 [hep-ph]
y2
MR2 log (q /MR)
2
(2 p )
3m
M
R
n log (q /M )
~
R
(2 p v)2
New physics below Planck scale Small Yukawas,
MR < 107 GeV
Leptogenesis ?
M. Fabbrichesi
Cancellation?
AYS
“Partial” SUSY?
- No hierarchy problem (even without SUSY)
- testable at LHC, new particles at 0.1 – few TeV scale
- LNV decays
Higgs
Triplet
Two loops
Low
scale
Inverse
seesaw
Neutralino as
RH neutrino
Connection
to Dark
Matter
M. Shaposhnikov et al
Everything below EW scale
 small Yukawa couplings
L
very
small
split
very
small
mixing
R
Few 100 MeV –
GeV
BAU
split ~ eV
WDM
3 - 10 kev
Normal
Mass
hierarchy
EW seesaw
- generate light
mass of neutrinos
- generate via oscillations
lepton asymmetry
in the Universe
- can be produced in
B-decays (BR ~ 10-10 )
- warm dark
matter
- radiative decays 
3.5 kev line
Higgs inflation
Nothing new below
Planck scale
Very light sector
which may include
- new scalar bosons, majorons, axions,
- new fermions (sterile neutrinos, baryonic nu) ,
- new gauge bosons (e.g. Dark photons)
M. Pospelov
Maybe related to Dark energy, MAVAN
Generate finite neutrino masses, usual Dirac masses can be
suppressed by seesaw with MR = MPl or multi singlet mechanism
eV scale Seesaw with RH neutrinos
for sterile anomalies LSND/ MiniBooNE ....
Tests:
A. De Gouvea
5th force searches experiments
Modification of dynamics of neutrino oscillations
Checks of standard oscillation formulas,
searches for deviations
In a spirit two types of
new physics and partial
relations
UPMNS =
VCKM+
From charged leptons or
Dirac matrices of charged
leptons and neutrinos
CKM type new physics
In general, has similar hierarchical
structure determined (as in
Wolfenstein parametrization) by
powers of
l = sin qC
C. Giunti, M. Tanimoto
H. Minakata, A Y S
UX
Related to mechanism of
neutrino mass generation
New neutrino structure
Related to (any) mechanism
that explains smallness of
neutrino mass
Should be fixed to reproduce
correct Lepton mixing angles
VCKM ~ I
UX ~ UTBM
q13 ~ ½ qc
Pheno. level
C. Giunti, M. Tanimoto
H. Minakata, A Y S
……………………………….
can be obtained in the context of
UPMNS = VCKM+ UX
if
UX = U23(p/2) U12
e.g. UX = UBM, UTBM
Realized in QLC
(Quark-Lepton Complementarity)
TBM-Cabibbo scheme
S. F. King et al
U12 (qc) U23(p/2)
permutation - to reduce the lepton mixing matrix
to the standard form leads to
q13~ ½ qc
sin 2q13~ ½sin2qC
The same value with completely
different implications
relation
~
½sin2qC
Dm212
O(1) Dm 2
32
sin2q13
¼
?
sin2q12sin2q23
~ ½cos2 2q23
implications
Quark-Lepton Complementarity
GUT, family symmetry, …
``Naturalness’’ , absence of
fine tuning of mass matrix
Analogy with quark mixing
relation
universal nm - nt – symmetry
violation
1/2
q13 = 2
> 0.025
Mixing anarchy
(p/4 - q23)
Eby,Frampton,
Matsuzaki
UPMNS ~ VCKM+ UX
No CPV
If the only source of CP violation
sinq13 sin dCP = (-cos q23) sinq13q sindq
l
sin dCP ~ l3/s13 ~ l2 ~ 0.046
dCP ~ - d or p + d
l3
B. Dasgupta, A.S.
dq = 1.2 +/- 0.08 rad
where d = (s13q /s13) c23 sin dq
If the phase dCP deviates substantially from 0 or p, new sources of CPV
beyond CKM should exists (e.g. from the RH sector) or another framework
New sources may have specific symmetries or structures which lead to particular
values of dCP e.g. -p /2, and q - l unification will give just small corrections
neglecting terms of the order ~ l3
sin dCP = s13-1 [sin(am + dX)Vud|Xe3| – sin ae |Vcd|Xm3 ]
here am , dX and ae are parameters of the RH neutrinos
Some special values of dCP can be obtained under certain assumptions
if Xe3 = 0 we have
sin dCP ~ – sin ae
if ae = p /2
dCP ~ 3p/2
One can find structure of the RH sector which lead to these conditions
B Dasgupta A.S
mDn ~ mDq
Ux is the matrix diagonalizes
MX = - mDdiag UR+ (MR)-1 UR* mDdiag
Here
mD = UL (mD diag) UR+
In contrast to quarks for Majorana neutrinos the RH rotation that
diagonalizes mD becomes relevant and contributes to PMNS
In the LR symmetric basis UX = UR US
From seesaw
Minimal extension is the L- R symmetry:
UR = UL ~ VCKM*
and no CPV in MR
Seesaw can enhance this small CPV effect
so that resulting phase in PMNS is large
Vub = ½ Vus Vcb
sinq13 ~ ½ sinq12 sinq23
The same relations between coupling strength between generations
Similar structure of mass matrices but with different
expansion parameter
ll = 1 - lq
Realization:
Fritzsch Anzatz similar to quark sector,
RH neutrinos with equal masses
Expectations:
Normal mass hierarhy,
relation between masses and mixing
Flavor alignment in mass matrix
mixing
ns
qaS2
dm ~ qaS2 mS
5 - 10 keV
2 10-11
(1 – 2) 10-8 eV
0.5 - 2 eV
0.02
1 MeV
- Warm Dark
matter
- Pulsar kick
- LSND, MB
- Reactor
Ga anomalies
- Extra radiation
- Solar neutrinos
- Extra radiation
in the Universe
1 keV
1 eV
10-3 eV
(2 – 4) 10-3 eV
10-3
0.02 eV
10-6 eV
Compare with large elements
of the mass matrix 0.02 eV
mn = ma + dm
Original active mass
matrix e.g. from see-saw
ma = 0.025 eV
For keV
dm << ma
For eV
dm ~ ma
For meV
dm << ma
Induced mass matrix
due to mixing with nu sterile
Decouples from generation of the light neutrino
masses argument that this is not RH neutrino
but has some other origin
Not a small perturbation
dm can change structure (symmetries)
of the original mass matrix completely
be origin of difference of
and
can be be considered as very small
perturbation of the 3n system
New structure (but physics is the same)
1
Ln(F) - 3/2
LHF
Through this portal
neutrino gets mass
where F is the fermionic operator
nL
H
S
nR
s
S
s
S
S
s
S
S
nR is the key to the solution
of the riddle?
s
Neutrino new physics
S
Scale
symmetries
Two different types of new physics are involved in explanation of
data: the CKM type common to quarks and leptons and physics
responsible for smallness of neutrino mass and large lepton
mixing. The latter may have certain symmetries
It makes sense to identify the second one which explains the
difference between the quarks and leptons
Still generation of quark and neutrino masses can be essentially
independent
High (GUT) scale new physics: still appealing
EW scale:
see LHC14 results
Sub eV –eV scale:
interesting, worth to explore
New neutrino physics may have certain symmetries which leads to
specific values of mixing angles and CP phase. Phase from CKM
part is strongly suppressed
Sterile neutrinos may be the key to solution to a riddle