massive neutrinos in a grounds-up approach with quark-lepton similarity

Amarjit SoniHanoi Aug. '061

MASSIVE NEUTRINOS IN A GROUNDS-UP APPROACH

WITH QUARK-LEPTON SIMILARITY

Amarjit Soni

HET, BNL

([email protected])

with David Atwood & Shaouly Bar-Shalom

Based on: Phys. Lett. B )2006(…&


OUTLINE• Introduction• Two Higgs doublet model for the top quark )t2HDM(• Incorporating the leptons in a “natural” set up -> a two

Higgs doublet model “for the 3rd generation”)3g2HDM(….invoke quark<->lepton similarity

• Masses, mixing angles & -oscillations in the 3g2HDM• Leptogenesis in the 3g2HDM : significantly enhanced• CP-asymmetry -> evading )usual( bound on )lightest(• Majorana mass and on the consequent reheating temp. • Summary & outlook


Introduction

Gonzales-Garcia, hepph/0410030; Fogli et al, hepph/0506083


Tν

1ννν DRD

mMmm

Introduction

• 2 monumental discoveries of the 90’s:mt ~ mGold >> mu,d,c,s,b

m 0 << eV

A strong hint for

Large Dirac -mass :

Super-heavy Majorana neutrinos :

GUT

2t

ν Λ

m~m

tm~mD

GUTm~MR

Based on the beautiful seesaw mechanism:

Are they related?


The goal of this work to suggest a natural relation between the:

1( large mt 2( observed -oscilations

3( superheavy Majorana mass scale

in a two Higgs doublet model, based on a grounds-up approach with quark-lepton similarity

the 2HDM “for the 3rd generation” )3g2HDM(

(assumes same status for the top-quark and the 3rd generation rh-)


Main output of the model

•“Predictions ”•42.90 > atm < 45.20

•-0.960 > 13 < 1.360

• In fact model leads to a simple relation :atm ~ π /4 - | 13 |• The CP asymmetry for leptogenesis • via )N1

-> l φ1 ( is significantly

enhanced •over models with 1 Higgs doublet or over SUSY-like

models


Two Higgs doublet model for the top quark [Das & Kao’96]

I( To accommodate the huge mass of the top quark,the Yukawa’s are chosen so that the second Higgs

doublet, with a much larger VEV than the 1st one couplesONLY to the top quark; the 1st Higgs doublet couples toall the other quarks and leptons…giving rise naturally to

a large tan β =v2/v1>>1 and a large top mass.

(t2HDM)


Incorporating the ν’s

•II(We propose a very simple generalization

•of t2HDM in which the second Higgs doublet, φ2 )with a much larger VEV(

couples not only to the top quark but also to the 3rd generation N.

•


The Two Higgs doublet Model “for the 3rd generation” )3g2HDM(

322,11

21

~~

~~

NLYNLYeLY

tQYc

uQYdQY

tLqLRqLe

RtLu

R

RqL

uRqL

d

YL /2NN jiijNM YLLL SM

N = r.h. Majorana neutrinos

A simple Extension of the 2HDM “for the top quark” (Das&Kao PLB1996(:

• Basic idea: large top mass is quite naturally accounted for by assuming vt/vq)=tanβ(>>1 t couples only to the top-quarkq couples to all other quarks

KEY PARAMETER of the MODEL tanβ)>>1(

A minimal LEET which captures the dominant features of phenomenology, and models some underlying dynamics of EW symmetry breaking relevant to distances much shorter

than the EW- scale


Two Key Points

•t2HDM may be regarded as an LEET for an underlying model of EWSB such as top-

condensation model )Bardeen, Hill and Lidner( or the top-color model )Hill( or in fact models

based on EXTRA-DIM e.g. RS

•Since NFC is not being implemented in Higgs couplings, we should expect

•necessarily fcnc )ex. Of Mod III( but very restrictive as fcnc involves only tc, tu and NOT

d,s.b


New&rich phenomenology of the 3g2HDM in the quark sector

• Enhanced H+cb Yukawa: H+cb Vtb )not Vcb!(

• Enhanced H0cc Yukawa: H0cc mctan )not

mc/tan !(

• New tree-level FC H0tc & H0tu couplings )no FCNC in d-quark sector!(

implications for: CPV in B-physics )Kiers,Soni,Wu: PRD1999, PRD2000(

FC Z-decays )Atwood,Bar-Shalom,Eilam,Soni: PRD2002(

b-jet & c-jet physics in hadron colliders


3g2HDM )cont.(

Our Anzats:

Quark-lepton similarity:

)SIGNIFICANT REDUCTION in # of params.(

)Y2(13=0 : avoid fine-tuning for -oscilation (e.g., (Y1)31= (Y2)13<< (Y1,2)ij13,31 from vanishingly small overlap of

corresponding N & L wave-functions in ED-models )Raidal&Strumia PLB2003(or from some flavor symmetry of the underlying short-distance theory)

{see, e.g. Grimus, Joshipura, Lavoura & Tanimoto, EuPhJC2004}

c00

c00

000

Y,

0δb0

0ba

0ba

Y νu,2

νu,1

2u2

ν21

u11 YYY&YYY


Implementing quark-lepton simlarity

•Note that the same elements (a,b,c..) in the•Yukawa matrix appear for quarks, ν •To get u-quark-ordering right: •a~O)10-3(,b~O)10-1(,c~O)1(•also for neutrinos.•This key assumption of quark-lepton similarity

renders the scenario with normal •hierarchy most natural


3g2HDM )cont.(

Our Anzats : Quark-lepton similarity u2

ν2

u11 YY&YY

ctδb0

ctba

0bav

m2q

D

t=tan ~ O)10( key parameter

Seesaw in the basis : )ε,ε,diag(εM M3M2M1NM

M3

22

M1

2

M2

2

M1

2

2q0

tc

aba

2M

vm

,, With:

2

0T-1N mmMmm

DD

mu ~ avq mc ~ bvq mt ~ cvq t a ~ O)10-3( b ~ O)10-1( c ~ O)1(

#of Params: 4 + 3


-oscillations )cont.(

Masses and mix. Angles:

r

rf

r

rgr

mm

fgmm

fgmm

r

r

f

g

r

r

2

2,

2

||,

~2~

cos2sin1~

sin2sin1~

2

)(~,2~2tan,

)(

2~2tan

2

03

122

120

2

122

120

1

2/31312223

3N

2t

M

m2

2

vct

2

vcm

2M

v

tc

qtt

2q

M3

22

0m

Normal hierarchy )m3>>m2>>m1( & Natural Mass Scales

2sol2

2atm3

Δm~m

Δm~m

GeV

GeV

13GeV10~

2sol

2qΔm~m

0ν

2q

15

2atm

2t

N

10Δm2m

~M

10~Δm

m2~M

q2sol

0ν

3

vvv 2/

heaviest M

M mass-scale

t-ν-N Seesaw Connection


Correlations in the mixing angles

•Study a scatter plot of the allowed ranges

•subject to the 3 σ allowed limits. This is done by randomly varying the 3 input

parameters )ε,r,δ( with a sample of 3X106

points.


Numerical Results & Implications mixing angles

masses


Numbers for -oscillations

at 3

at 99% CL3g2HDMExisting Bound

e.g. Gonzalez-Garcia, hep-ph/0410030

7.310-5 < m2sol < 9.110-57.310-5 < m2

sol < 9.310-5

110-3 < m2atm < 3.710-31.610-3 < m2

atm < 3.610-

3

3g2HDMExisting Bounde.g. Gonzalez-Garcia, hep-ph/0410030

28.00 > sol < 36.0027.90 > sol < 37.80

-0.960 > 13 < 1.360|13| < 11.70mix

ing

angl

es

mas

ses

42.90 > atm < 45.2035.30 > atm < 55.40


• best fitted parameters from -oscillation:

• quark-lepton similarity:

a ~ O)10-3( , b ~ O)10-1( , c ~ O)1(

r ~ 1 , ~ 0.6 , ~ 5.3

Heavy Majorana Spectrum in the 3g2HDM

GeV10M,GeV10M,GeV10M

10ε,10ε,10ε7

N11

N15

N

6M1

2M2

2M3

123

Will find: MN1 ~ 109 – 1010 GeV << MN2 , MN3


2

1

1i

N

NNN M

Mεε

11

221

1 )(

)(Im

16

3)(N

11

11

YY

YYL q

asym!MSSMorSMmaxthe2

atmNMAXN

MAXNab2

atm

2sol3g2HDM

N

v

mMε

εm

mεε

1

1

11

16

3

2 βtan )sin2( 2

In the 3g2HDM )with MN1 << MN2 , MN3 (:

a,b=arg)a,b(

Leptogenesis in the 3g2HDM

Washout determined by the “decay parameter” K=N1/H)T~MN1(For e.g., 109<MN1/GeV< 1010 )6<K<60(

1.2141.2 1N

M106~K

0.5

)a good fit to the numerical solution of the B-eqs. – see e.g., Di Bari, hep-ph/0406115(

CPV asymmetry in the decays Ni L

s

na

s

nMTY

s

n Lsph

BBLNNN

Liii

)(

asymmetry washout# density of Ni

spheleron processes

CP-asymmetry from:


Origin of the enhanced CP asymmetry

•The enhancement in the CP asy. in this model is due to the presence of the 2nd Higgs doublet

which sets the scale of EWSB )v2 ( but that is now decoupled

•from v1 that determines the light neutrino mass spectrum…Indeed CP asy. in our model is

enhanced over SM and SUSY-models by tan2β ~100


Overall Baryon asym. in the 3g2HDM

)sin2(βtanη 2ab2

t

2.2N2

sol17

N3B

m

Mmε10ε101.4

s

n1

1

2.1)(GeV

For best fitted parameters ), m2sol( & tan ~ O)10(:

)sin2( abN31B

1M102

s

n 2.2/GeV

Compatible with observed value nB/s ~ 8.510-11 if e.g., MN1 ~ 1010 GeV & sin2)b- a( ~ 0.1

Or )max. CP(: MN1 ~ 109 GeV & sin2)b- a( ~ 1


• 3g2HDM: an effective grounds-up approach based on quark-lepton similaritykey parameter: tan O)10( in order to explain mt

• Predictions:– a triple t - - N seesaw connection: – Easily fits -oscillation data but gives a very restricted:

• -0.960 < 13 < 1.360 )3(• 42.90 < atm < 45.20 )3(

– MN1 ~ 109-1010 GeV, MN2 ~ 1011 GeV, MN3~ 1015 GeV– Baryogenesis through Leptogenesis with:

CP-asym. ~ tan2·max)SM or MSSM(

SUMMARY & OUTLOOK

3

3

N

2t

ν M

mm

atm ~ π /4 - | 13|

<-Favors normal hierarchy


Backups


Discrete Symmetry for t2HDM

Das&Kao, PLB’96


Leptogenesis from CP-asymmetry Ni in the decays Ni L

2

1

1i

N

NNN M

Mεε

11

221

11 )(

)(Im

16

3)(N

11

11

YY

YYL

)sin2(βtan2ab2

t

N2sol

3g2HDMN m

Mmεε 1

1

8

3

a,b=arg)a,b(

Ni in the 3g2HDM )for MN1 << MN2 , MN3 (:

s

na

s

nMTY

s

n Lsph

BBLNNN

Liii

)(


spheleron processesCPV/L#V asymmetry


Leptogenesis in the 3g2HDM )cont.(

washout: determind by the “decay parameter” K which measures the amount of asymmetry-damping caused by the inverse N1 decay:

GeV/1

3-

11

1

N

10O)10~a

N

Plank23

N

N

M

106

M

Ma104.8~

(M~H)T

ΓK

)

1.2

141.2 GeV

M106~

K

0.51N

for e.g., 109<MN1/GeV< 1010 6<K<60 )the mildly strong washout regime: strong enough to be almost independent of the initial conditions but not too strong to result in a significant efficiency loss(



In the 3g2HDM )with MN1 << MN2 , MN3 (:

)sin2(βtan2

abN2t

2sol3g2HDM

N εMm

mε

11

16

3

a,b=arg)a,b(

Leptogenesis in the 3g2HDM

Washout determined by the “decay parameter” K=N1/H)T~MN1(For e.g., 109<MN1/GeV< 1010 )6<K<60(

1.2141.2 1N

M106~K

0.5


CPV asymmetry in the decays Ni L

s

na

s

nMTY

s

n Lsph

BBLNNN

Liii

)(


spheleron processes

CP-asymmetry from:

2

1

1i

N

NNN M

Mεε

11

221

1 )(

)(Im

16

3)(N

11

11

YY

YYL q

massive neutrinos in a grounds-up approach with quark-lepton similarity

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