NEUTRINOLESS DOUBLE BETA DECAY ANGULAR CORRELATION AND NEW PHYSICS Dmitry Zhuridov Particles and...

NEUTRINOLESS DOUBLE BETA NEUTRINOLESS DOUBLE BETA DECAYDECAY

ANGULAR CORRELATIONANGULAR CORRELATIONAND NEW PHYSICSAND NEW PHYSICS

NEUTRINOLESS DOUBLE BETA NEUTRINOLESS DOUBLE BETA DECAYDECAY

ANGULAR CORRELATIONANGULAR CORRELATIONAND NEW PHYSICSAND NEW PHYSICS

Dmitry Zhuridov

Particles and Fields Journal club

Department of Physics

National Tsing Hua University

Dmitry Zhuridov

Particles and Fields Journal club

Department of Physics

National Tsing Hua University

2007/11/06 High Energy Physics Journal club 2

The talk is based mostly on the paper:

Probing new physics in the neutrinoless double beta decayusing electron angular correlation.A. Ali (DESY) , A.V. Borisov, D.V. Zhuridov (Moscow State U.) . DESY-07-097, Jun 2007. 36pp. e-Print: arXiv:0706.4165 [hep-ph] (to appear in Phyical Review D)


Popularity of the themePopularity of the theme

M. Doi, T. Kotani, E. Takasugi, Prog.Theor.Phys.Suppl.83 (1985) 329 T. Tomoda, Rep.Prog.Phys.54 (1991) 133 S.L. Adler et al., Phys.Rev.D11 (1975) 74 H. Pas, M. Hirsch, H.V. Klapdor-Kleingrothaus, S.G. Kovalenko, Phys.Lett.B453

(1999) 26

SPIRES-HEP: FIND TITLE NEUTRINOLESS DOUBLE BETA DECAY 470 FIND K NEUTRINOLESS DOUBLE BETA DECAY 476

E-print arXiv: Abstract: NEUTRINOLESS DOUBLE BETA DECAY 1991-1995 29 1996-2000 139 2001-2005 251 2006-p.t. 87


ContentsContents

Introduction Neutrinoless Double Beta Decay Angular Correlation in Long-Range Mechanism Analysis of the Angular Correlation Conclusion


IntroductionIntroduction

2 2 2 0ij i j

m m m SNO, Super-Kamiokande, KamLAND – ν oscillations

Neutrinos have non-zero masses and they mix with each other

Bounds on the neutrino masses:2 2 5 2212 2 3 231

7.9 10

2.3 10sol

atm

m m эВ

m m эВ

1, 30.75 0.25 ( )i ii

im эВ m эВ

1/ 22 2

12.05eff eff

ei ie ei

m U m эВ m m


Dirac field can be constructed from two Majorana fields

Dirac field has additional freedom of phase trasformation

It is largely anticipated that the neutrinos are Majorana particles:

Correspondence between Dirac and Majoana fields


Other possible mechanisms

How to induce small neutrino masses?

Model with scalar triplet: Model with right-handed neutrino and scalar singlet:

In Zee model (with charged scalar singlet and additional scalar doublets) Majorana neutrino masses arise at one loop level;

In models with doubly charged scalar singlet Majorana neutrino masses arise at two loop level;

Models with effective nonrenormalizable term in Lagrangian:


See-saw mechanism


( ) ( 2) 2A Z A Z e

{ n

n }pp

e

e

( )A Z ( 2)A Z

Lepton number is changed by 2 units.02 decay is forbidden in the SM.

Extended version of the SM could contain tiny nonrenormalizable terms that violate LN and allow 02 decay.

0 2 decay

Neutrinoless Double Beta DecayNeutrinoless Double Beta Decay


Two possible classes of mechanisms for the 02 decay:

Long range Short range(with the light s in the intermediate state)

Probable mechanisms of LN violation may include exchanges by:

Majorana neutrinosScalar bilinears, e.g. doubly charged dileptons SUSY particlesLeptoquarksRight-handed W_R bosons etc.

d

d

u

u

e

e

d

d

uu

e

e


According to the Schechter-Valle theorem, any mechanism inducing the 02 decay produces an effective Majorana mass for the neutrino, which must therefore contribute to this decay.

Purpose: to examine the possibility to discriminate among the various possible mechanisms contributing to the 02 decays using

the information on the angular correlation of the final electrons.

dd

u ue e


Angular Distribution in Long-Range Angular Distribution in Long-Range MechanismMechanism

Most general Lorentz invariant effective Lagrangian for the long-range mechanism of 0ν2β decay is:

L,R

& are leptonic & hadronic currents of definite tensor structure

and chirality; , =V A, S P, T ; is PMNS mixing matrix;

encode new physics.

ei

i

j J

U

' ', 0 2 2 , , ,

V A currents (Doi M., Kotani T., Takasugi E. (1985))

, , , .V A i V A V A V AV VV A i l V A i ei V A i ei V A i eiei

V V

g ge U V U V V

g g

1 1 1 1 *, ( ) , ( ) , ( ) ( )

1 *, ( )

1 1

2 4

1

8

(Hirsch M., Klapdor H.V., Kovalenko S.G. (1996))

, 2 , 4 ,

.R

R

M

V A n S P n S P n nV A i q RR ni S P i LL ni S P i q LR LR ni

T nT i q LR ni

RPV MSSM

U U U

U

( ) ( ) ( ) ( )

2 2 2 2- 2 22 2 21

2 4 4 4, , , .

Model with LQ (Hirsch M., Klapdor-Kleingrothaus H.V., Kovalenko S.G. (1996))

L L R RS V S VV A V A S P S PV S

V A V A S P S PS V S VF F F FV S

M M M MG G G GM M


Approximations:• leading order in the Fermi constant • leading contribution of the parameters \epsilon• relativistic electrons and non-relativistic nucleons • S_{1/2} and P_{1/2} waves for the outgoing electrons


Expressions for Expressions for AA for one for one ∈, considered at a time∈, considered at a time


Expressions for Expressions for BB for one for one ∈ at a time∈ at a time


, ,

2

, , ,

01

, , with effective Majorana masses: m ,

, , ;

cos , with the relative phases: arg

In these tables:

L L

L R L R

ei iie e

T TS P S P V A V AS P ei S P i i V A ei V A i i T ei T i i

i i i

i i

m mU m

m m

m U m m U m m U m

c

* *1

2 2

0 1 0 1

, arg ...

, .

V A V AV A V A

C D

A B

( , ) ( , )

( , ) ( , )0 0 0 0

The quantities , , and are expressed through

the intergated phase space factors , , , and

the combinations of nuclear parameters.

SP T SP Ti i i i

SP T SP Tk k k k

C C D D

A A B B

The expressions associated with the coefficients confirm the results

of Doi et al. (1985), while the expressions associated with the other

coefficients transcend the earlier work.

V AV A


-15 -1

+ 76

The integrated kinematic - and -factors [in 10 yr ]

for the 0 0 transition of the 0 2 decay of Ge.

A B


AnalysiAnalysiss of of the Ethe Electron lectron AAngular ngular CCorrelationorrelation

If the ``nonstandard" effects, are zero then K = B01/A01. Its values are given in the Table for various decaying nuclei of current experimental interest:

-The presence of the ``nonstandard" parameters , , or

does not change significantly the form of the angular correlation.

The presence of the ``nonstandard" parameters ,

L R

R L

T TV A S PV A S P T T

V AV A

, or

does change this correlation.

L R

L R

T TS PS P T T

The angular correlation coefficient K for various SM extensions for decays of :

76 Ge.


Constraints on the couplings of the effective LQ-quark-lepton interactions:

Particular cases for the parameter space:

22High Energy Physics Journal club2007/11/06

1a 1b

2a 2b


Angular correlation in left-right symmetric modelsAngular correlation in left-right symmetric models

LWFor the model (2) (2) (1) using the condition m :

, arctan / , with = .

R

R L

L R W

V AW W V A ei eiV A

V A

SU SU U m

m m U V

1

6 -7Using 80.4 GeV for the values 10 , 5 10

we have got the correlation shown in Figs 3, 4.LW Wm m


10^3*ς

-6

-7

Figs 3a, 3b.

=10

Figs 4a, 4b.

=5 10

10^3*ς


-6

Experiments in the 0 2 decay would measure / and .

Experiments at the Tevatron and the LHC can measure / .

Differential width vs. cos for =10 :

L R

L R

W W ei ei

W W

m m U V

m m


ConclusionConclusion We have presented a detailed study of the electron

angular correlation for the long range mechanism of 02 decays in a general theoretical context. This information, together with the ability of observing these decays in several nuclei, would help greatly in identifying the dominant mechanism underlying these decays.

The running experimental facility that in principle can measure the electron angular correlation in the 02 decay NEMO3 possibly has no the sufficient sensitivity. The proposed facilities are SuperNEMO, MOON and EXO. We have argued that there is a strong case in building at least one of them.

NEUTRINOLESS DOUBLE BETA DECAY ANGULAR CORRELATION AND NEW PHYSICS Dmitry Zhuridov Particles and...

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