Matter Effect on Neutrino Oscillation from Universality Violation

in Neutral Current Interactions

Naotoshi Okamura (YITP)

and

Minako Honda (Ochanomizu Univ.)

Yee Kao (Virginia Tech.)

Alexey Pronin (Virginia Tech.)

Tatsu Takeuchi (Virginia Tech.)

NuFact06(@UC Irvine) 2006.8.29

based on hep-ph/0602115 hep-ph/0603268 hep-ph/0609xxx

Introduction

SM : universality of NC

1. Can interactions between neutrinos and matter due to New Physics have any effect on neutrino oscillations ?

New Physics : “no” universality of NC : new source of potential

-beam

Motivation

e-

e-

p

p

n

n

2. Can such effects be measured experimentallyand be used to constrain New Physics ?

Universality Violation in NCI

beam

Matter effect

(b) neutral current interaction

(a) charged current interaction

etc...

processesex) MSSM with

lead to the NC universality violation

In a number of models beyond the SM,the universality of the couplingscan be violated through radiative corrections.

LEP/ OPAL, DELPHI, L3, ALEPH, SLD

NO CONSTRAINTindividual decay

LEP @ CERN

The experimental constraints 1~invisible decay width~

No information is availableon the individual decay widths into each flavor

invisible

LEP invisible decay width (total width is constrained.)

cf ) Z couplings to charged leptons

LEP/ OPAL, DELPHI, L3, ALEPH, SLD

The experimental constraints 2~individual~

CHARM, CHARM II @ CERN (’80s)

Z couplings to neutrinos

PLB180,303(1986), PLB320,203(1994)

0.9-1.2

•The theoretical possibility of universality violation in many models•The weakness of the current experimental bounds

It would be interesting to analyze the effect of such a violation on neutrino oscillations.

PLB180,303(1986), PLB320,203(1994)

CHARM, CHARM II

New Physics that can contribute to neutrino oscillations:• R-parity violating couplings

• Gauged B-(Le+L+L)• Z’ in Topcolor assisted Technicolor• Leptoquarks that couple different generations•etc.

Li

Li

˜ d Lj

dRk

dRk

ijk

ijk

Direct exchange of New Particle

e.g.)

npe ,,

Z

zg

zg npe ,,

• Introduction• Matter effect

– effective potentials for neutrinos in matterW and Z exchange

– effective Hamiltonian In the presence of NC universality violation

• Can we see ? (A hypothetical experiment)Fermilab NuMI beam

Hyper-Kamiokande detector (1⇒Mt)

• Constraints on New Physics (e.g. leptoquarks)• Summary

Plan of Talk

Matter Effect (Effective Potential)the mixing angles

the Probability

in ordinary matter

The effective potentials(W & Z exchange)

neutral current interaction

charged current interaction

The effective HamiltonianU:MNS matrix

: measure of universality violation in NC

： effective mixing matrix

： effective mass-squares

central valueof CHARM

CC NC

derived from universality violationin Neutral Current interaction

effective mixing angles (normal hierarchy)

13

231

13

12

221

132323

231

12

221

13

1312

13

231

1313

2

0~

2sin2

~

22sin

22

~

2

~

neutrino

a

m

a

m

c

s

m

a

a

m

c

c

a

m

0~

2

~

2sin2

~

~

neutrino-anti

231

2323

12

221

12

13

231

1313

m

a

a

m

a

m

21

231

231

221

~ ,10~GeV:~ ofregion in the

24.0~15.0m

of powersin expanded case, 0

OOEOm

a

m

(details in our paper)

effective mixing angles (inverted hierarchy)

0~

2

~

2sin22

~

~

neutrino

231

2323

12

221

12

13

231

1313

m

a

a

m

a

m

13

231

13

12

221

132323

231

12

221

13

1312

13

231

1313

2

0~

2sin2

~

22sin

2

~

2

~

neutrino-anti

a

m

a

m

c

s

m

a

a

m

c

c

a

m

21

231

231

221

~ ,10~GeV:~ ofregion in the

24.0~15.0m

of powersin expanded case, 0

OOEOm

a

m

(details in our paper)

shift of effective mixing by

2

312 m

a

neutrino anti-neutrino

normal

hierarchy is shifted by is shifted by

inverted

hierarchy is shifted by is shifted by

2312 m

a

2

312 m

a

12

~

23

~

2

312 m

a

23

~

12

~

24.0~15.0 , ,10~GeV:

231

22121

231 m

mOOEO

m

a

Sum up the calculation,

(details in our paper)In the region of

Survival Probability ()

2313323131223122

3121312212

2

3

2

2

3122

3

2

3212

2

2

2

2

~~~ ,~~~~~~

~sin

~sin

2

~sin

2

~sin4

~~2

2

~sin

~1

~4

2

~sin

~1

~41

~

scUsssccU

UU

UUUUP

212

221

213

23121

212

231

232

323122

~

2

~sin

22sin1

~

0~

,~~

cos~

hierarchy) (normal neutrino

cδmcδm

m

aP

UU

212

221

213

23132

322

231

232

233232

~

2

~sin

22sin1

~

~sin

~ ,

~cos

~hierarchy) (normal neutrino-anti

cδmcδm

ξδm

aθννP

UU

μμ

212

221

213

23131

312

231

232

2332

~

2

~sin

22sin1

~

~sin

~ ,0

~hierarchy) (inverted neutrino

cmcm

m

aP

UU

212

221

213

23121

212

231

232

323122

~

2

~sin

22sin1

~

0~

,~~

cos~

hierarchy) (inverted neutrino-anti

cmcm

m

aP

UU

The oscillation probabilities ( L=9,120km )

neutrino beam energy [ GeV ] neutrino beam energy [ GeV ]

normal hierarchy inverted hierarchy

@17GeV @17GeV

The oscillation probabilities ( L=9,120km )

neutrino beam energy [ GeV ] neutrino beam energy [ GeV ]

normal hierarchy inverted hierarchy

40%

@17GeV

40%

@17GeV

atm</4

Can we measured experimentally ?one example (FNAL – HK)

to Japan

small value () large matter effect high energy (E~O(10)GeV) long base-line (L~O(104)km)

from J-PARC (Japan)

USA-Japan

Fermilab

MINOS @Soudan

HK (1Mt)

732km

9,120km~732x12

Fermilab (NuMI) Hyper-Kamiokande [ L~9,120 km ]

@17GeV revent/Mt/y1300

9120

732kt1000200

2

2

HK

SoudanHKSoudanHK

L

LVNN

We can expecta non-

negligible event rate

even when oscillationis taken into account

Main Injector @ Fermilab

17GeV

NuMI Beam (LOI)

no oscillation

The expected number of events @ HK

neutrino beam energy [ GeV ]

nu

mb

er

of

ev

ents

0 5 10 15 20 25 30

500

1000

1500

2000

2500

3000

3500

4000

0

oscillation dip17GeV

We can expect the green lineto be clearly distinguishablefrom the blue or pink lines.

after 5 years of data taking (1Mton)

The constrains on universality violation

-0.03 -0.02 -0.01 0 0.01 0.02 0.030

20

40

60

80

100

99%C.L.95%C.L.

90%C.L.

~0.015~0.005

1year

3years

5years

10yearsmuch tighter constraintsthan that from

CHARM and CHARMII

much tighter constraintsthan that from

CHARM and CHARMII

2 / 14dof (8GeV-22GeV)

0.025-0.025

Constraints on New Physics (e.g. Leptoquarks)

S : scalar, V : vector, subscript : dim of SU(2) rep.

ML

Q [T

eV]

ML

Q [T

eV]

22

22

W

LQLQ

MgMg

S2

V3

This result is highly sensitive to the value of sin2(223)

Summary

The violation effects normal inverted

mixing angle

oscillation probability

L=9,120 km

17GeV

We investigated the matter effect on neutrino oscillation

from universality violation in neutral current interactions.

Fermilab Hyper-Kamiokande⇒If sin2(223) is NOT too close to 1,

we may be able to either observe this effect, or

impose a much tighter constraint on universality violation

than that from CHARM and CHARMII.

Thank you very muchfor your attention

Yeah!!

Yeah!!