Bounds on Neutrino Non-Standard Interactions

Enrique Fernández-Martínez MPI für Physik Munich

Based on collaborations with:S. Antusch, J. Baumann, C. Biggio, M. Blennow,

B. Gavela and J. López Pavón

Introduction: NSI

Generic new physics affecting oscillations can beparameterized as 4-fermion Non-Standard Interactions:

fPflPG RLLF ,22

Production or detection of a associated to a l

So that

→ n →pl

Y. Grossman hep-ph/9507344

Direct bounds on prod/det NSI

C. Biggio, M. Blennow and EFM 0907.0097

dPuPlG RLLud

F ,22

13.0016.0011.0

013.0078.0106.2

041.0025.0041.05ud

Bounds order ~10-2

ePPG LLe

F

22

03.003.0025.0

03.003.0025.0

03.003.0025.0e

From decays and zero distance oscillations

Non-Standard scattering off matter can also be parameterized as 4-fermion Non-Standard Interactions:

fPfPG RLLm

F ,22

so that

Introduction: NSI

→in matter f = e, u, d

5.01.044.0

1.003.01.0

44.01.014.0em

Direct bounds on matter NSI

If matter NSI are uncorrelated to production and detectiondirect bounds are mainly from scattering off e and nuclei

S. Davidson, C. Peña garay, N. Rius and A. Santamaria hep-ph/0302093J. Barranco, O. G. Miranda, C. A. Moura and J. W. F. Valle hep-ph/0512195

J. Barranco, O. G. Miranda, C. A. Moura and J. W. F. Valle 0711.0698C. Biggio, M. Blennow and EFM 0902.0607

fPfPG RLLm

F ,22

Rather weak bounds… …can they be saturated avoiding additional constraints?

305.05.0

05.0008.005.0

5.005.01um

605.05.0

05.0015.005.0

5.005.06.0dm

Gauge invariance

However fPfPG RLLm

F ,22

is related to fPflPlG RLLm

F ,22

by gauge invariance and very strong bounds exist

me 610

me 210

m 210

→ e → e in nucleaidecays

S. Bergmann et al. hep-ph/0004049Z. Berezhiani and A. Rossi hep-ph/0111147

Large NSI?

We search for gauge invariant SM extensions satisfying:

Matter NSI are generated at tree level

4-charged fermion ops not generated at the same level

No cancellations between diagrams with different messenger particles to avoid constraints

The Higgs Mechanism is responsible for EWSBS. Antusch, J. Baumann and EFM 0807.1003B. Gavela, D. Hernández, T. Ota and W. Winter 0809.3451

Large NSI?

At d=6 only one direct possibility: charged scalar singlet

M. Bilenky and A. Santamaria hep-ph/9310302

cc LiLLiL 22

Large NSI?

Very constrained:

F. Cuypers and S. Davidson hep-ph/9310302S. Antusch, J. Baumann and EFM 0807.1003

→ e decays decaysCKM unitarity

Since = - only , and ≠0

SSB

2

v

LiHHiL tc22

LiHiHiL t2

*2

Large NSI?

At d=6 indirect way: fermion singlets

SSB

2

v

Ki

A. Broncano, M. B. Gavela and E. Jenkins hep-ph/0210192

Effective Lagrangian• 3 light • all unitarity violation from NP with Λ > v • flavour universality

.....cos

..2

chPZg

chPlWg

MKiL LW

L

Diagonal mass and canonical kinetic terms

.....cos

..2

chPZg

chPlWg

MKiL LW

L

• 3 light • all unitarity violation from NP with Λ > v • flavour universality

.....)(cos

..2

† chNNPZg

chNPlWg

miL jijLiW

iiLiiiiii

Effective Lagrangian

.....)(cos

..2

† chNNPZg

chNPlWg

miL jijLiW

iiLiiiiii

Diagonal mass and canonical kinetic terms

.....cos

..2

chPZg

chPlWg

MKiL LW

L

iiN N is not unitary

• 3 light • all unitarity violation from NP with Λ > v • flavour universality

Effective Lagrangian

(NN†) from decays

• Rare leptons decays

††

2†

NNNN

NN

W

il l

Info on (NN†)

Wi

l

††

†

NNNN

NN

ee

iZ

j

††

†

NNNN

NN

ee

• W decays

• Invisible Z

• Universality tests

†

†

NN

NN

Info on(NN†)

After integrating out W and Z neutrino NSI induced

(NN†) from decays

333

345

353

†

106.2100.1106.1

100.1102.8109.5

106.1109.5100.2

2 NNExperimentally

E. Nardi, E. Roulet and D. Tommasini hep-ph/9503228D. Tommasini, G. Barenboim, J. Bernabeu and C. Jarlskog hep-ph/9503228S. Antusch, C. Biggio, EFM, B. Gavela and J. López Pavón hep-ph/0607020

S. Antusch, J. Baumann and EFM 0807.1003

Non-Unitarity at a NF

Golden channel at NF is sensitive to e

disappearance channel linearly sensitive to through matter effects

Near detectors can improve the bounds on e and

Combination of near and far detectors sensitive to the new CP phases

S. Antusch, M. Blennow, EFM and J. López-pavón 0903.3986See also EFM, B. Gavela, J. López Pavón and O. Yasuda hep-ph/0703098;

S. Goswami and T. Ota 0802.1434; G. Altarelli and D. Meloni 0809.1041,….

Large NSI?

At d=8 more freedom

Can add 2 H to break the symmetry between and l with the

vev

There are 3 topologies to induce effective d=8 ops with

HHLLff legs:

-v2/2 ff

ffLiHHiL t

2

*2

Z. Berezhiani and A. Rossi hep-ph/0111147; S. Davidson et al hep-ph/0302093

Large NSI?

We found three classes satisfying the requirements:

Large NSI?

We found three classes satisfying the requirements:

Just contributes to the scalar propagator after EWSB

Same as the d=6 realization with the scalar singlet

v2/2 cc LiLLiL 22

1

Large NSI?

We found three classes satisfying the requirements:

The Higgs coupled to the NR selects after EWSB

-v2/2 ff

ffLiHHiL t

2

*2

2

Z. Berezhiani and A. Rossi hep-ph/0111147S. Davidson et al hep-ph/0302093

Large NSI?

But can be related to non-unitarity and constrained

1

22†

22

NNM

Yv

M

Yv

i i i

i

i

i 1

22†

22

NNM

Yv

M

Yv

j j j

j

j

j

Fij G10

2

Large NSI?

For the matter NSI

Where is the largest eigenvalue of

And additional source, detector and matter NSI aregenerated through non-unitarity by the d=6 op

Large NSI?

We found three classes satisfying the requirements:

Mixed case, Higgs selects one and scalar singlet S the other

3

Large NSI?

Can be related to non-unitarity and the d=6 antisymmetric op

3

1

22†

22

NNM

Yv

M

Yv

i i i

i

i

i j j Sj

j

Sj

j

Mv

Mv

2

2

Fij G10

Large NSI?

At d=8 we found no new ways of selecting

The d=6 constraints on non-unitarity and the scalar singlet

apply also to the d=8 realizations

What if we allow for cancellations among diagrams?

B. Gavela, D. Hernández, T. Ota and W. Winter 0809.3451

EELiHHiL t2

*2

Cancelling the 4-charged fermion ops.

S. Antusch, J. Baumann and EFM 0807.1003

NSI in loops

Even if we arrange to have

We can close the Higgs loop, the triplet terms vanishes and

NSIs and 4 charged fermion ops induced with equal strength

EELiHHiLM

O t2

*24

EEHHLLHHLLM

O ††42

EELLk

M

O2

2

4 162

C. Biggio, M. Blennow and EFM 0902.0607

NSI in loops

EELLk

M

O2

2

4 162

The loop contribution is a quadratic divergence

The coefficient k depends on the full theory completion

If no new physics below NSI scale = M

Extra fine-tuning required at loop level to have k=0 or loop contribution dominates when 1/162 > v2/M2

C. Biggio, M. Blennow and EFM 0902.0607

Conclusions

Models leading “naturally” to NSI imply:

O(10-2-10-3) bounds on the NSI

Relations between matter and production/detection NSI

Probing O(10-3) NSI at future facilities very challenging but not impossible, near detectors excellent probes

Saturating the mild model-independent bounds on matter NSI and decoupling them from production/detection requires strong fine tuning

NSI in loops

Even if we arrange to have

We can close the Higgs loop, the triplet terms vanishes and

NSIs and 4 charged fermion ops induced with equal strength

EELiHHiLM

O t2

*24

EEHHLLHHLLM

O ††42

EELLk

M

O2

2

4 162

C. Biggio, M. Blennow and EFM 0902.0607

NSI in loops

Even if we arrange to have

We can close the Higgs loop, the triplet terms vanishes and

NSIs and 4 charged fermion ops induced with equal strength

EELiHHiLM

O t2

*24

EEHHLLHHLLM

O ††42

EELLk

M

O2

2

4 162

C. Biggio, M. Blennow and EFM 0902.0607

NSI in loops

These loops are related by gauge invariance:

Used to set loop bounds on ethrough the log

divergence

However the log cancels when adding the diagrams…

+

C. Biggio, M. Blennow and EFM 0902.0607

NSI in loops

EELLk

M

O2

2

4 162

The loop contribution is a quadratic divergence

The coefficient k depends on the full theory completion:

Without cancellations k O(1) At least MW → old bounds are recovered

e8·10-4

If no other new physics = M → NSI = 4CF if 1/162 > v2/M2

Allowing cancellations also at loop level k = 0

Only direct 0.1 bound on e

C. Biggio, M. Blennow and EFM 0902.0607

Large NSI?

General basis for d=8 ops. with two fermions and two H

Z. Berezhiani and A. Rossi hep-ph/0111147B. Gavela, D. Hernández, T. Ota and W. Winter 0809.3451

2 left + 2 right

4 left

Large NSI?

To cancel the 4-charged fermion ops:

but

and

EELiHHiL t2

*2

HHLiLLiL cc †22

LLLiHHiL t2

*2

LiHHiLLL t2

*2

NR

NR

NR

scalar singlet

after a Fierz transformation

Large NSI?

There is always a 4 charged fermion op that needs canceling

Toy model

B. Gavela, D. Hernández, T. Ota and W. Winter 0809.3451

EELiHHiL t2

*2

Cancelling the 4-charged fermion ops.

Other models for masses

Type I seesawMinkowski, Gell-Mann, Ramond, Slansky, Yanagida, Glashow, Mohapatra, Senjanovic, …

NR fermionic singlet

Type II seesawMagg, Wetterich, Lazarides, Shafi, Mohapatra, Senjanovic, Schecter, Valle, …

scalar triplet

Type III seesawFoot, Lew, He, Joshi, Ma, Roy, Hambye et al., Bajc et al., Dorsner, Fileviez-Perez

R fermionic triplet

Different d=6 ops

Type II:• LFV 4-fermions interactions

Type I:• non-unitary mixing in CC• FCNC for

Type III:• non-unitary mixing in CC• FCNC for • FCNC for charged leptons

A. Abada, C. Biggio, F. Bonnet, B. Gavela and T. Hambye 0707.4058

Types II and III induce flavour violation in the charged lepton sectorStronger constraints than in Type I

Low scale seesaws

The d=5 and d=6 operators are independent

Approximate U(1)L symmetry can keep d=5 (neutrino mass) small and allow for observable d=6 effects

See e.g. A. Abada, C. Biggio, F. Bonnet, B. Gavela and T. Hambye 0707.4058

Inverse (Type I) seesaw Type II seesaw L= 1 -1 1

DNNtD mMMmd 11

5

DND mMmd 2†6

25 4

M

Yd

2

†

6

M

YYd

Magg, Wetterich, Lazarides, Shafi, Mohapatra, Senjanovic, Schecter, Valle,…

Wyler, Wolfenstein, Mohapatra, Valle, Bernabeu, Santamaría, Vidal, Mendez, González-García, Branco, Grimus, Lavoura, Kersten, Smirnov,….

<< M