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Neutrino Mass and Flavor Physics R. N. Mohapatra

Neutrino Mass and Flavor Physics R. N. Mohapatra

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Page 1: Neutrino Mass and Flavor Physics R. N. Mohapatra

Neutrino Mass and Flavor Physics

R. N. Mohapatra

Page 2: Neutrino Mass and Flavor Physics R. N. Mohapatra

Neutrino Mass- What do we know ?

Masses: ; Mixings: ; Overall mass scale: < .1- 1 eV (roughly) To be determined (expts in progress or

planning) (i) Majorana or Dirac ? (ii) Mass ordering: NH or IH (iii) Value of (iv) Any possible CP violation ? (v) Leptonic unitarity

252 1067.7 eVmsol 232 1039.2 eVmAtm

;312.sin 122 466.sin 23

2 04.sin 132

13

Page 3: Neutrino Mass and Flavor Physics R. N. Mohapatra

Many experiments on the way

(i) Majorana or Dirac

(ii) Absolute mass scale: (iii) Mass ordering: (iv) Value of (v) CP phase

13

0

Page 4: Neutrino Mass and Flavor Physics R. N. Mohapatra

Plan of the talk Neutrino mass New physics beyond SM:

Raises two new issues: New mass scale to explain why

Is it accessible at the LHC ?

New approach to flavor : Can we have a unified understanding quark- lepton mixings ?

lqmm ,

Page 5: Neutrino Mass and Flavor Physics R. N. Mohapatra

Why ?

Seesaw Paradigm: Add heavy right handed neutrinos to SM

and play seesaw:

Seesaw scale is the new physics scale !! Two different seesaws depending on whether N

Majorana or Dirac

RN

lqmm ,

Page 6: Neutrino Mass and Flavor Physics R. N. Mohapatra

Type I seesaw Majorana

Breaks B-L : New scale and new symmetry beyond SM. After EWSB -Neutrino majorana

key parameter to test seesaw type I

NNMHNLhL RRY

RM

R

wk

M

vhm

22

Minkowski,Gell-Mann, Ramond Slansky,Yanagida, Mohapatra,Senjanovic,Glashow

Page 7: Neutrino Mass and Flavor Physics R. N. Mohapatra

Inverse Seesaw Mostly Dirac i.e. add another

singlet

Seesaw parameter testing or larger (RNM’86;

RNM, Valle’86)

M

Mhv

hv

wk

wk

0

0

00D

TD mMMmm 11

),,( SRL

S

RNS SS M

310~

M

mD

Page 8: Neutrino Mass and Flavor Physics R. N. Mohapatra

New physics signal for simplest seesaw

Strength given by or mixing:

e.g. collider production:

Leptonic non-unitarity: Both negligible for type I seesaw but

observable for inverse seesaw MN ~ TeV Situation different with gauge forces !!

N

Page 9: Neutrino Mass and Flavor Physics R. N. Mohapatra

1. Seesaw (B-L) scale Neutrino masses do not determine seesaw scale ; MU~ GeV

Both and high seesaw scale indication for

SUSYGUTs; No collider signals ! (Common Lore) B-L scale at TeV LHC signals with only gauge forces; No GUTs with type I.

B-L at TeV and GUTs can co-exist: since possible

(Dev,

RNM’09)

tD mm GeVM R1410 1610

eD mm

Inverse seesaw

tD mm

tD mm

Page 10: Neutrino Mass and Flavor Physics R. N. Mohapatra

A concrete realization: Low scale B-L in Left-Right

NR Gauge group: New W’ and Z’ Fermion assignment

Two Avatars of LR: type I Inverse seesaw +

LBRL USUSU )1()2()2(

L

L

d

u

R

R

d

u

L

L

e

R

R

e

P

P

)0,2,2( )2,1,3()2,3,1(; LR

LW

RW ,',ZZ

)0,2,2( )1,2,1()1,1,2( RL

Page 11: Neutrino Mass and Flavor Physics R. N. Mohapatra

Bound on SUSYLR scale from Low energy data

M_WR > 2 TeV from a combination of KL-KS, epsilon, d_n together.(uncertainty from long distance contribution);

(An,Ji,Zhang’07)

Page 12: Neutrino Mass and Flavor Physics R. N. Mohapatra

Bounds from Nu-less double beta decay

New contributions from WR-N exchange (only for Case I) (RNM, 86; Hirsch, Klapdor, Panella 96)

Diagram:

From Ge76:

Page 13: Neutrino Mass and Flavor Physics R. N. Mohapatra

Seesaw signal from Nu contribution:

Inverse hierarchy Normal hierarchy

Punch line: Suppose long baseline

and nonzero signal for (+ RP if susy )

TeV WR and type I

0

0231 m

0

Page 14: Neutrino Mass and Flavor Physics R. N. Mohapatra

Constraints on Seesaw scale from coupling unification:

TeV type I does not grand unify: Landau Pole

(Kopp, Lindner, Niro, Underwood’09) (Parida, Sarkar, Majee, Raichaudhuri’09)

Discovery of type I signal at LHC will rule out GUTs.

Page 15: Neutrino Mass and Flavor Physics R. N. Mohapatra

TeV Inverse Seesaw (LR) Inverse seesaw does unify and give realstic

model: with both WR and Z’ in TeV range; MSSM GUT SUSYLR GUT

Look for not only susy but also WR, Z’, N at LHC:(Dev, RNM, 09; PRD);

Page 16: Neutrino Mass and Flavor Physics R. N. Mohapatra

SO(10) as the GUT theory

{16 }- spinor for all matter

Type I: only unification route:

Inverse seesaw:

TeVMGeVM RU ;1016

GeVM BLU16

, 102

Page 17: Neutrino Mass and Flavor Physics R. N. Mohapatra

Radiative Breaking of B-L and SM

Positive spartner mass square at GUT scale-

RGE turns them negaitve much like SM with large t-mass

(Dev, RNM’10)

Page 18: Neutrino Mass and Flavor Physics R. N. Mohapatra

LHC Signals for seesaw LHC production of WR: ; N-decay: type I Inv. Seesaw:

Type I case: (Keung, Senjanovic;

Han, Perez,Huang,Li, Wang; Del Aguila,

Aguilar-Saavedra; Azuelos,..)

Inverse seesaw: Only

Trileptons; no same sign dileptons(30 fb^-1)(del Aguila,Aguilar-Saavedra, de Blas)

NlWdu R NNZuu '

jjlN ll,

lljjlN ,

Page 19: Neutrino Mass and Flavor Physics R. N. Mohapatra

Other TeV scale Type I Signals

TeV type I Seesaw requires B-L=2 Higgs:

Doubly charged Higgs can have sub-TeV mass. Decays to lepton pairs

Four lepton signals at LHC

2

12

1

0

,,ee ,, ee

LHC signals for type I seesaw will rule out simple GUTs

Page 20: Neutrino Mass and Flavor Physics R. N. Mohapatra

New Dark matter in TeV scale Inverse seesaw:

If super-partner of RH neutrino is the lightest, it will be stable due to R-parity- become DM.

Soft breaking:

Lightest linear combination is dark matter:

SSNSfvLHNhWW RMSSM

SNBNHLASSMNNMLL SMSSMsoft

~~~~~~~~ 22

Minimal Type I case: Usual Bino-Higgsino

Page 21: Neutrino Mass and Flavor Physics R. N. Mohapatra

Dark matter in type I GUT vs TeV scale Inverse seesaw:

Inverse seesaw case: (Fornengo, Arina, Bazzochi, Romao, Valle’08)

New DMNew DM : :Two contributions to relic density: Z’ exchange (Matchev, Lee, Nasri) No or small Z’

effect

c~

TeVM Z 5.2'

Page 22: Neutrino Mass and Flavor Physics R. N. Mohapatra

2. Understanding Flavor

(i) Mass hierarchies(ii) Strange mixing patterns: Leptons: Quarks:

UPMNS= UCKM =

(Harrison, Perkins, Scott; He, Zee,Wolfenstein; Xing,..)

1

1

1

23

2

3

Page 23: Neutrino Mass and Flavor Physics R. N. Mohapatra

Mass Texture Up-quark and charged lepton diagonal

basis:

= Cabibbo angle

123

223

335

bd mM

133

313

331

11

11

M

~i

Page 24: Neutrino Mass and Flavor Physics R. N. Mohapatra

Strategy for texture Key idea: SM has a large sym for zero fermion

masses : [SU(3)]^5;

Choose subgroup: Discrete subgroup with 3-d. rep.

Replace Yukawa’s by scalar fields (flavons);

Minima of the flavon theory determines Yukawas:

Page 25: Neutrino Mass and Flavor Physics R. N. Mohapatra

Application to Neutrinos

Successful Family symmetries for TBM:

Flavon fields are triplets: (Ma, Rajasekaran; Babu, Ma, Valle, King, Ross; Altarelli, Feruglio, Chen, Mahanthappa;

Everett, Ramond; Luhn, Nasri, Yu, RNM, Hagedorn, Morissi,…..)

Grand unified theories: SU(5)

)(2 S ),...3( 2n

How can we unify with quarks ?

Page 26: Neutrino Mass and Flavor Physics R. N. Mohapatra

High scale Ansatz for unifying quark-lepton flavor

(Dutta, Mimura, RNM’PRD-09)

f diagonal. Anarchic M0, quark mixings small while

lepton mixings large.

explains mass hierarchies +

dd rMM 0 Lfvm uu MM 0

0,, Mldu ll rMM 0

mmb Rank 1 M0

A

B

Page 27: Neutrino Mass and Flavor Physics R. N. Mohapatra

SUSY SO(10) realization Fermions in {16}:

16mx16m={10}H+{120}H+{126}H

Fermion masses from Yukawas as in SM:

(Babu, Mohapatra, 93)

HHHY hfhL ]10,120[1616'6211616101616

Page 28: Neutrino Mass and Flavor Physics R. N. Mohapatra

Neutrino mass formula in GUT scale B-L in SO(10):

Type II seesaw:

TD

BLD M

fvMfvm

1

Lazaridis, Shafi, Wetterich; R.N.M.,Senjanovic’81

Page 29: Neutrino Mass and Flavor Physics R. N. Mohapatra

SO(10) with GUT scale B-L unified approach to flavor

fermion mass formulae:

(Babu, Mohapatra’92) Bajc, Senjanovic, Vissani’03

For f, h’ << h, yields ansatz part A at MU; Rank from flavor symmetry: e.g.

fvm

),..27(,4 S

Page 30: Neutrino Mass and Flavor Physics R. N. Mohapatra

An S4 xSO(10)- example Solar mass Dutta, Mimura, RNM

arXiv:0911.2242

Bottom-tau: and

Leading order PMNS: U(Harrison, Perkins, Scott; He, Zee, Xing; Wolfenstein)

Corrections: Testable Bjorken, King, Pakvasa Ferrandis; Chen, Mahanthappa

Double beta mass 3 meV.

catm

solar

m

m

mmb smm 3

05.023

13 c

Page 31: Neutrino Mass and Flavor Physics R. N. Mohapatra

Prospects for measuring Reactor, Long base line e.g. T2K, NoVA: (Lindner, Huber,Schwetz,Winter’09)

Our prediction 01.02sin 132

Page 32: Neutrino Mass and Flavor Physics R. N. Mohapatra

Conclusion: TeV scale WR compatible with

SO(10) GUT; Can be tested at LHC; New dark matter candidate:

New unified approach to flavor based on typeII+ SO(10)- testable via theta_13.

Page 33: Neutrino Mass and Flavor Physics R. N. Mohapatra

WR, Z’ at LHC_14

Production : WR Z’

Page 34: Neutrino Mass and Flavor Physics R. N. Mohapatra

Signals for Type I case Two and three lepton signals in colliders

N-decay gives signal:

Like sign dilepton plus trilepton+ (Han, Perez, Li, Del Aguila, Aguilar Saavedra,…)

NlWdu R

jjlN ll,

E

NNZuu '

l

Page 35: Neutrino Mass and Flavor Physics R. N. Mohapatra

Inverse seesaw case N is mostly Dirac

Collider leptonic signal from WR production:

No like sign dilepton but only trileptons +

WlN

NlWdu R

E

Page 36: Neutrino Mass and Flavor Physics R. N. Mohapatra

Distinguishing between seesaws

Observation of relative abundance of like sign dileptons vs trileptons can distinguish between TeV scale Inverse seesaw vs type I seesaw

(Aguilar-Saavedra)

Type I

Inverse