Sandhya Choubey Harish-Chandra Research Institute ...lss.fnal.gov/conf/C0606131/6.2Choubey.pdf · WHAT WE CAN LEARN FROM ATMOSPHERIC NEUTRINOS Sandhya Choubey Harish-Chandra Research

WHAT WE CAN LEARN FROM ATMOSPHERIC NEUTRINOS

Sandhya Choubey

Harish-Chandra Research Institute, Allahabad, India

Neutrino 2006XXII International Conference on Neutrino Physics and Astrophysics

Santa Fe, 14-19 June 2006

Goals for the Future / Plan of Talk

SANDHYA CHOUBEY WHAT CAN WE LEARN FROM ATMOSPHERIC NEUTRINOS Neutrino 2006, 16.06.06 – p.1/41


Confirmation of oscillations of atmospheric neutrinos

Precision measurement of ∆m231 and θ23

Measuring the deviation of θ23 from its maximal value

Determining the octant of θ23

Determining the sign of ∆m231

Compare and contrast the capabilities of large water Cerenkov(SK50) and magnetized iron detectors (INO-ICAL) for all of theabove. (See hep-ph/0604182 for discussion on Liquid Argon.)

Using atmospheric neutrinos to constrain new physics

OSANDHYA CHOUBEY WHAT CAN WE LEARN FROM ATMOSPHERIC NEUTRINOS Neutrino 2006, 16.06.06 – p.2/41























































Confirmation of Oscillations of Atmospheric Neutrinos


Confirmation of Oscillations of Atmospheric NeutrinosSmoking Gun Signal for νµ − ντ Oscillations

SK collab, Koshio talk, NANP ’05

Its important to observe the characteristic “dip” in L/E



2 2.5 30

20

40

60

80

100

120

140

2 2.5 3

INO collaboration



2 2.5 30

20

40

60

80

100

120

140

2 2.5 3

INO collaborationThe first oscillation dip should be clearly observable


Precision Measurement of ∆m231 and θ23



Experiment |∆m231| sin2 θ23

Current 30% 34%




Current 30% 34%MINOS+CNGS 13% 38%

T2K (5 yrs) 6% 22%NOνA (5 yrs) 13% 42%Combination 4.5% 20%

Huber et al hep-ph/0403068






SK20 (1.84 MTy) 17% 24%


Gonzalez-Garcia et al, hep-ph/0408170






SK20 (1.84 MTy) 17% 24%

INO (250 kTy) 10% 30%



INO Collaboration


Three Generation Oscillation Probabilities


Muon Neutrino Survival Probability

lim∆m2

21→ 0

Pµµ(L, E) = 1 − P 1

µµ(L, E) − P 2

µµ(L, E) − P 3

µµ(L, E)

P 1

µµ(L, E) = sin2 θM13 sin2 2θ23 sin2 (A + ∆m2

31) − (∆m231)

M

8EL

P 2

µµ(L, E) = cos2 θM13 sin2 2θ23 sin2 (A + ∆m2

31) + (∆m231)

M

8EL

P 3

µµ(L, E) = sin2 2θM13 sin4 θ23 sin2 (∆m2

31)M

4EL


Muon Neutrino Survival Probability

lim∆m2

21→ 0

Pµµ(L, E) = 1 − P 1

µµ(L, E) − P 2

µµ(L, E) − P 3

µµ(L, E)

P 1

µµ(L, E) = sin2 θM13 sin2 2θ23 sin2 (A + ∆m2

31) − (∆m231)

M

8EL

P 2

µµ(L, E) = cos2 θM13 sin2 2θ23 sin2 (A + ∆m2

31) + (∆m231)

M

8EL

P 3

µµ(L, E) = sin2 2θM13 sin4 θ23 sin2 (∆m2

31)M

4EL

Dependence on θ23 in the form sin4 θ23

Octant sensitivity is expected to be good


Large Matter Effects in νµ Survival Probability

1 3 5 7 9E (GeV)

0

0.2

0.4

0.6

0.8

P µµ

0

0.2

0.4

0.6

0.8

P µµ

0

0.2

0.4

0.6

0.8

1

P µµ sin2θ23=0.50 (matter)

sin2θ23=0.50 (vacuum)

sin2θ23=0.36 (matter)


L=1000 km

L=3000 km

L=5000 km

L=7000 km

L=9000 km

L=11000 km

1 3 5 7 9 11E (GeV)

S.C. and P. Roy, hep-ph/0509197



1 3 5 7 9E (GeV)

0

0.2

0.4

0.6

0.8

P µµ

SPMAX

SPMIN2SPMIN1

0

0.2

0.4

0.6

0.8

P µµ

0

0.2

0.4

0.6

0.8

1

P µµ sin2θ23=0.50 (matter)




L=1000 km

L=3000 km

L=5000 km

L=7000 km

L=9000 km

L=11000 km

1 3 5 7 9 11E (GeV)

S.C. and P. Roy, hep-ph/0509197



1 3 5 7 9E (GeV)

0

0.2

0.4

0.6

0.8

Pµ

µ

SPMAX

SPMIN2SPMIN1

0

0.2

0.4

0.6

0.8

Pµ

µ

0

0.2

0.4

0.6

0.8

1

Pµ

µ sin2θ23=0.50 (matter)




L=1000 km

L=3000 km

L=5000 km

L=7000 km

L=9000 km

L=11000 km

1 3 5 7 9 11E (GeV)

Max effect for L ' 7000 km andE ' 5 GeV ⇒ (ESPMAX ' Eres)



1 3 5 7 9E (GeV)

0

0.2

0.4

0.6

0.8

Pµ

µ

SPMAX

SPMIN2SPMIN1

0

0.2

0.4

0.6

0.8

Pµ

µ

0

0.2

0.4

0.6

0.8

1

Pµ





L=1000 km

L=3000 km

L=5000 km

L=7000 km

L=9000 km

L=11000 km

1 3 5 7 9 11E (GeV)


Pµµ decreases (increases) at SP-MAX (SPMIN) due to matter effects



1 3 5 7 9E (GeV)

0

0.2

0.4

0.6

0.8

Pµ

µ

SPMAX

SPMIN2SPMIN1

0

0.2

0.4

0.6

0.8

Pµ

µ

0

0.2

0.4

0.6

0.8

1

Pµ





L=1000 km

L=3000 km

L=5000 km

L=7000 km

L=9000 km

L=11000 km

1 3 5 7 9 11E (GeV)



Sign of the earth matter effectsdepends on both E and L



1 3 5 7 9E (GeV)

0

0.2

0.4

0.6

0.8

Pµ

µ

SPMAX

SPMIN2SPMIN1

0

0.2

0.4

0.6

0.8

Pµ

µ

0

0.2

0.4

0.6

0.8

1

Pµ





L=1000 km

L=3000 km

L=5000 km

L=7000 km

L=9000 km

L=11000 km

1 3 5 7 9 11E (GeV)




Matter effects depend on thevalue of sin2 θ23



1 3 5 7 9E (GeV)

0

0.2

0.4

0.6

0.8

Pµ

µ

SPMAX

SPMIN2SPMIN1

0

0.2

0.4

0.6

0.8

Pµ

µ

0

0.2

0.4

0.6

0.8

1

Pµ





L=1000 km

L=3000 km

L=5000 km

L=7000 km

L=9000 km

L=11000 km

1 3 5 7 9 11E (GeV)




Matter effects depend on thevalue of sin2 θ23

Most important to choose the bins properly in both E and L


Very Large Matter Effects in νµ ↔ νe Probability


Very Large Matter Effects in νµ ↔ νe Probabilities

lim∆m2

21→ 0

Pµe(L, E) = sin2 θ23 sin2 2θM13 sin2 (∆m2

31)ML

4E



lim∆m2

21→ 0


31)ML

4E

1 3 5 7 9E (GeV)

0

0.1

0.2

0.3

0.4

0.5

P µe

sin2θ23=0.5(matter)

sin2θ23=0.5(vacuum)

1 3 5 7 9E (GeV)

L=7000 km L=9000 km



lim∆m2

21→ 0


31)ML

4E

1 3 5 7 9E (GeV)

0

0.1

0.2

0.3

0.4

0.5

P µe



1 3 5 7 9E (GeV)

L=7000 km L=9000 km

Above ∼ 3 GeV, matter effects increase Pµe for all E and L



lim∆m2

21→ 0


31)ML

4E

1 3 5 7 9E (GeV)

0

0.1

0.2

0.3

0.4

0.5

P µe



1 3 5 7 9E (GeV)

L=7000 km L=9000 km

Sub-dominant ∆m221 oscillations in Pµe is also crucial


Atmospheric Neutrino Events


Atmospheric Neutrino EventsChange in number of muon events:

Nµ = N0

µPµµ + N0

e Peµ

= N0

µ

[

Pµµ +1

rPeµ

]

; (where r =N0

µ

N0e

)

1 −Nµ

N0µ

' (P 1

µµ + P 2

µµ) + (P 3

µµ)′s2

23(s2

23 −1

r)

(P 3

µµ)′ = sin2 2θM13 sin2 (∆m2

31)M

4EL

Can be used to study maximality and octant of θ23

Can be used to study the neutrino mass hierarchy

∆m221 and δCP bring in small effects


Atmospheric Neutrino EventsChange in number of electron events:

Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)

+ sin θ23 cos θ23 r Re

[

A∗

13A12 exp(−iδCP )

]



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]

∆m221-driven oscillation effect



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]


Brings an excess (depletion) in the sub-GeV electron eventsample for sin2 θ23 < 0.5(> 0.5)



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]


Brings an excess (depletion) in the sub-GeV electron eventsample for sin2 θ23 < 0.5(> 0.5)

Can be used for studying maximality and octant of θ23



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]

θ13-driven oscillation effect



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]

θ13-driven oscillation effectReduces the excess (depletion) in the sub-GeV electron event

sample for sin2 θ23 < 0.5(> 0.5) – thats the bad part!!



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]



Contains big earth matter effects resulting in sizable change inmulti-GeV electron event sample, with the change being sin2 θ23

dependent – thats the excellent part!!



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]








Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]






Can be used for studying the neutrino mass hierarchy



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]

“interference” term which depends on δCP



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]


It might cancel the effect of the ∆m221 and θ13 terms depending on

the value of δCP – bad bad bad...



Ne

N0e

− 1 ' sin2 2θM12 sin2

(

(∆m221)

ML

4E

)

× (r cos2 θ23 − 1)

+ sin2 2θM13 sin2

(

(∆m231)

ML

4E

)

× (r sin2 θ23 − 1)


[

A∗


]


It might cancel the effect of the ∆m221 and θ13 terms depending on

the value of δCP – bad bad bad...

But it might tell us if δCP = 0 or π (Fogli et al. hep-ph/0506083)


Atmospheric Neutrino Events in MTon Water Detector



−1 −0.6 −0.2 0.2 0.6 1cosξ

0

1000

2000

3000

4000

5000

even

ts (S

K50

)

∆m2

31=2.5x10−3

eV2

sin22θ23=0.91

sin2θ13=0.00

SGe SGµ

MGeMGµ

0

4000

8000

12000

16000

20000

even

ts (S

K50

)

sin2θ23=0.35

sin2θ23=0.65

∆m2

21=0

−1 −0.6 −0.2 0.2 0.6 1cosξ

0

2000

4000

6000

8000

10000

12000

even

ts (S

K50

)

0

4000

8000

12000

16000

20000

even

ts (S

K50

)

These are just 2-gen νµ → ντ oscillationsOSANDHYA CHOUBEY WHAT CAN WE LEARN FROM ATMOSPHERIC NEUTRINOS Neutrino 2006, 16.06.06 – p.20/41


−1 −0.6 −0.2 0.2 0.6 1cosξ

0

1000

2000

3000

4000

5000

even

ts (S

K50

)

∆m2

31=2.5x10−3

eV2

sin22θ23=0.91

sin2θ13=0.00

SGe SGµ

MGeMGµ

0

4000

8000

12000

16000

20000

even

ts (S

K50

)

sin2θ23=0.35

sin2θ23=0.65

∆m2

21=8x10−5

eV2

−1 −0.6 −0.2 0.2 0.6 1cosξ

0

2000

4000

6000

8000

10000

12000

even

ts (S

K50

)

0

4000

8000

12000

16000

20000

even

ts (S

K50

)

∆m221-driven oscillations bring in octant sensitivity in SGe events



−1 −0.6 −0.2 0.2 0.6 1cosξ

0

1000

2000

3000

4000

5000

even

ts (S

K50

)

sin22θ23=0.91

sin2θ13=0.04

SGe SGµ

MGeMGµ

∆m2

31=2.5x10−3

eV2

0

4000

8000

12000

16000

20000

even

ts (S

K50

)

sin2θ23=0.35

sin2θ23=0.65

∆m2

21=8x10−5

eV2

−1 −0.6 −0.2 0.2 0.6 1cosξ

0

2000

4000

6000

8000

10000

12000

even

ts (S

K50

)

0

4000

8000

12000

16000

20000

even

ts (S

K50

)

θ13 brings in more octant sensitivity through matter effectsSANDHYA CHOUBEY WHAT CAN WE LEARN FROM ATMOSPHERIC NEUTRINOS Neutrino 2006, 16.06.06 – p.20/41

Atmospheric Neutrino Events in INO-ICAL


Atmospheric Neutrino Events in INO-ICAL

1 3 5 7 9E (GeV)

−0.4

−0.3

−0.2

−0.1

0

0.1

UN/D

N −

UA/D

A

−0.4

−0.3

−0.2

−0.1

0

0.1

UN/D

N −

UA/D

A

−0.4

−0.3

−0.2

−0.1

0

0.1

0.2

UN/D

N −

UA/D

A

matter (s2

23=0.5)vacuum (s

2

23=0.5)matter (s

2

23=0.36)

1 3 5 7 9 11E (GeV)

|cξ|=|0−0.157|

|cξ|=|0.157−0.314|

|cξ|=|0.314−0.471|

|cξ|=|0.471−0.628|

|cξ|=|0.628−0.785|

|cξ|=|0.785−0.942|

S.C and P. Roy hep-ph/0509197SANDHYA CHOUBEY WHAT CAN WE LEARN FROM ATMOSPHERIC NEUTRINOS Neutrino 2006, 16.06.06 – p.22/41

Testing Maximality of θ23


Testing maximality of θ23

|D| within 14%LBL combined

Antusch, et al,

hep-ph/0404268




Antusch, et al,

hep-ph/0404268

|D| within 19%SK50

Gonzalez-Garcia, et al,

hep-ph/0408170




Antusch, et al,

hep-ph/0404268

|D| within 19%SK50


hep-ph/0408170

0.25 0.35 0.45 0.55 0.65 0.75sin

2θ23(true)

1

2

3

∆m2 31

(tru

e)[1

0−3 eV

2 ]

sin2θ13(true)=0.00

500 kTy

|D| within 25%INO-ICAL 500 kTy

S.C. and P. Roy,

hep-ph/0509197




Antusch, et al,

hep-ph/0404268

|D| within 19%SK50


hep-ph/0408170

0.25 0.35 0.45 0.55 0.65 0.75sin

2θ23(true)

1

2

3

∆m2 31

(tru

e)[1

0−3 eV

2 ]

sin2θ13(true)=0.00

500 kTy


S.C. and P. Roy,

hep-ph/0509197

Sensitivity to |D| ≡ |(sin2 θ23 − 0.5)| comparable to LBL expts




Antusch, et al,

hep-ph/0404268

0.25 0.35 0.45 0.55 0.65 0.75sin

2θ23(true)

1

2

3

∆m2 31

(tru

e)[1

0−3 eV

2 ]

sin2θ13(true)=0.00

|D| within 20%SK50

preliminary

.

0.25 0.35 0.45 0.55 0.65 0.75sin

2θ23(true)

1

2

3

∆m2 31

(tru

e)[1

0−3 eV

2 ]

sin2θ13(true)=0.00

500 kTy


S.C. and P. Roy,

hep-ph/0509197

Sensitivity to |D| ≡ |(sin2 θ23 − 0.5)| comparable to LBL expts




Antusch, et al,

hep-ph/0404268

0.25 0.35 0.45 0.55 0.65 0.75sin

2θ23(true)

1

2

3

∆m2 31

(tru

e)[1

0−3 eV

2 ]

sin2θ13(true)=0.00

|D| within 20%SK50

preliminary

.

0.25 0.35 0.45 0.55 0.65 0.75sin

2θ23(true)

1

2

3

∆m2 31

(tru

e)[1

0−3 eV

2 ]

sin2θ13(true)=0.04

500 kTy


S.C. and P. Roy,

hep-ph/0509197

Sensitivity to |D| in INO-ICAL improves marginally with θ13




Antusch, et al,

hep-ph/0404268

0.25 0.35 0.45 0.55 0.65 0.75sin

2θ23(true)

1

2

3

∆m2 31

(tru

e)[1

0−3 eV

2 ]

sin2θ13(true)=0.04

|D| within 11%SK50

preliminary

.

0.25 0.35 0.45 0.55 0.65 0.75sin

2θ23(true)

1

2

3

∆m2 31

(tru

e)[1

0−3 eV

2 ]

sin2θ13(true)=0.04

500 kTy


S.C. and P. Roy,

hep-ph/0509197

Sensitivity to |D| in INO-ICAL improves marginally with θ13

Sensitivity to |D| in SK50 improves remarkably with θ13


Resolving the θ23 Octant Ambiguity


Resolving the θ23 Octant Ambiguity with INO-ICAL

0.35 0.4 0.45 0.5 0.55 0.6 0.65sin

2θ23(true)

0

2

4

6

8

10

12

∆χ2 [s

in2 θ 23(true)

− sin2 θ 23(fa

lse)]

Normal Mass Ordering

0.35 0.4 0.45 0.5 0.55 0.6 0.65sin

2θ23(true)

Inverted Mass Ordering

sin2θ13(true)=0.04

sin2θ13(true)=0.03

sin2θ13(true)=0.02

sin2θ13(true)=0.01

1 MTonyr S.C and P. Roy hep-ph/0509197

sin2 θ23(false) can be excluded at 3σ if:

sin2 θ23(true) < 0.402 or > 0.592 for sin2 θ13(true) = 0.02,

sin2 θ23(true) < 0.421 or > 0.573 for sin2 θ13(true) = 0.04.


Resolving the θ23 Octant Ambiguity with SK50


sin2 θ23(false) can be excluded at 3σ if:sin2 θ23(true) < 0.36 or > 0.62 for sin2 θ13(true) = 0.00.



0.3 0.4 0.5 0.6 0.7sin

2θ23(true)

0

5

10

15

∆χ2

Blue Lines: sin2θ13(true)=0.00 Red Lines: sin

2θ13(true)=0.02

Solid Lines: no priors; Dashed Lines: external priors

Prelim

inary





0.3 0.4 0.5 0.6 0.7sin

2θ23(true)

0

5

10

15

∆χ2

Blue Lines: sin2θ13(true)=0.00 Red Lines: sin

2θ13(true)=0.02

Solid Lines: no priors; Dashed Lines: external priors

Prelim

inary



�

�

�

�

Sensitivity to octant of θ23

improves remarkably as θ13

increases from zero.


Resolving the sgn(∆m231) Ambiguity


Resolving the sgn(∆m231) Ambiguity with INO-ICAL

0 0.05 0.1 0.150

2

4

6

8

∆χ2 w

r hie

r for

400

0 ev

ents µ-like

2σ

0 0.05 0.1

true value of sin22θ

13

0

10

20

30

µ-likehigh

osc. params. fixed, external prior information, osc. params. freesolid: true hierarchy normal, dashed: true hierarchy inverted

0 0.05 0.1 0.150

5

10

15

20

3σ

3σ

e-like

4000 upward going events (Thomas Schwetz)Petcov and Schwetz, hep-ph/0511277



0 0.05 0.1 0.150

2

4

6

8

∆χ2 w

r hie

r for

400

0 ev

ents µ-like

2σ

0 0.05 0.1


13

0

10

20

30

µ-likehigh


0 0.05 0.1 0.150

5

10

15

20

3σ

3σ

e-like


The wrong hierarchy can be ruled out at 2σ with 4000 upwardgoing events for sin2 2θ13 = 0.1(sin2 θ13 = 0.026) and sin2 θ23 = 0.5



0 0.05 0.1 0.150

2

4

6

8

∆χ2 w

r hie

r for

400

0 ev

ents µ-like

2σ

0 0.05 0.1


13

0

10

20

30

µ-likehigh


0 0.05 0.1 0.150

5

10

15

20

3σ

3σ

e-like



Polamares-Ruiz,Petcov (2003)

Indumathi, Murthy (2004)

Ghoshal,Gandhi,Goswami,Mehta,UmaSankar (2004)



0 0.05 0.1 0.150

2

4

6

8

∆χ2 w

r hie

r for

400

0 ev

ents µ-like

2σ

0 0.05 0.1


13

0

10

20

30

µ-likehigh


0 0.05 0.1 0.150

5

10

15

20

3σ

3σ

e-like



Sensitivity increases with E and L resolution



0 0.05 0.1 0.150

2

4

6

8

∆χ2 w

r hie

r for

400

0 ev

ents µ-like

2σ

0 0.05 0.1


13

0

10

20

30

µ-likehigh


0 0.05 0.1 0.150

5

10

15

20

3σ

3σ

e-like



Sensitivity increases if it were possible to detect electrons



0 0.05 0.1 0.150

2

4

6

8

∆χ2 w

r hie

r for

400

0 ev

ents µ-like

2σ

0 0.05 0.1


13

0

10

20

30

µ-likehigh


0 0.05 0.1 0.150

5

10

15

20

3σ

3σ

e-like



Sensitivity increases with sin2 θ23


Resolving the sgn(∆m231) Ambiguity with SK50

0 0.01 0.02 0.03sin2θ13

0

2

4

6

8

10

12

14

16

∆χ2 IH

True Hierarchy is Normal

Prelim

inar

y

s2

23(true)=0.4 s2

23(true)=0.5 s2

23(true)=0.6solid: δCP=0



0 0.01 0.02 0.03sin2θ13

0

2

4

6

8

10

12

14

16

∆χ2 IH


Prelim

inar

y

s2

23(true)=0.4 s2

23(true)=0.5 s2

23(true)=0.6solid: δCP=0 dashed: δCP=free

Sensitivity drops appreciably due to δCP



0 0.01 0.02 0.03sin2θ13

0

2

4

6

8

10

12

14

16

∆χ2 IH


Prelim

inar

y

s2

23(true)=0.4 s2

23(true)=0.5 s2

23(true)=0.6solid: δCP=0 dashed: δCP=free

Sensitivity drops appreciably due to δCP

Resolving param degen:

T2K+ATM:hep-ph/0501037

βbeams+ATM:hep-ph/0603172


Searching for New Physics


Searching for New PhysicsNon-Standard neutrino-matter Interaction

Violation of Equivalence Principle

Lorentz Invariance Violation

Violation of CPT Symmetry

Neutrino Decay

Quantum Decoherence

(This list is not exhaustive.)


Searching for New Physics in INO-ICAL/SK50 like ExptsNon-Standard neutrino-matter Interaction

Violation of Equivalence Principle

Lorentz Invariance Violation

Violation of CPT Symmetry

Neutrino Decay

Quantum Decoherence

Each one has a distinctive L/E behavior

Oscillations go linearly as L/E

Atmospheric neutrinos have a very wide range of L/E

This L/E data can be used to probe new physics – INO-ICAL

Comparison of contained events and upward going muons inwater Cerenkov detectors can also be used


Searching for New Physics with Neutrino TelescopesNeutrino Telescopes have atmospheric ν’s as background

The atm ν’s seen will be of highest energies: (10−1-104) TeV

At these energies, standard neutrino oscillations are negligible

Any E or L dependence in the data will signify new physics





















102

103

104

105

Eµ [GeV]

0.6

0.8

1

1.2

1.4

1.6

1.8

2

pho

riz /

p vert

10-2810

-2710-2610

-25

10-24

Solid=νµ+ντ Dashed=νµ only

δc/c = vary, ξ = 45

pi = Ni / Niosc

vert=[-1.0, -0.6] horiz=[-0.6, -0.2]


ICECUBE






Morgan et al, astro-ph/0412618

ANTARES


Conclusions


ConclusionsOsc of atmospheric neutrinos will be confirmed by INO-ICAL

Precision on ∆m231 and θ23 can be improved to 17%(10%) and

24%(30%) respectively by SK20 and INO-ICAL(250 kTy)

|D| can to determined to within 20% (25%) by SK50(INO-ICAL(500 kTy)) if sin2 θ13(true) = 0

|D| can to determined to within 11% (23%) by SK50(INO-ICAL(500 kTy)) if sin2 θ13(true) = 0.04

Octant of θ23 can be determined with INO-ICAL(1 MTy) ifsin2 θ23(true) < 0.42 or > 0.57 for sin2 θ13(true) = 0.04

Octant of θ23 can be determined with SK50 ifsin2 θ23(true) < 0.38 or > 0.60 for sin2 θ13(true) = 0

Sensitivity to octant for SK50 improves remarkably if θ13 6= 0






















































Sensitivity to octant for SK50 improves remarkably if θ13 6= 0SANDHYA CHOUBEY WHAT CAN WE LEARN FROM ATMOSPHERIC NEUTRINOS Neutrino 2006, 16.06.06 – p.40/41

ConclusionsNeutrino mass hierarchy can be determined at 2σ at 4000upward going events at INO-ICAL if sin2 θ13(true) = 0.026 andsin2 θ23(true) = 0.5

Neutrino mass hierarchy can be determined at > 2σ at SK50 ifsin2 θ13(true) = 0.026 and sin2 θ23(true) = 0.5

However, the sensitivity to hierarchy at SK50 falls appreciablywhen δCP is allowed free

New Physics might be discovered/constrained usingatmospheric neutrinos





















I thank the organizers of Neutrino 2006, Harish-Chandra Research Institute,University of Oxford, INO collaboration, Srubabati Goswami, Michele Maltoni,Probir Roy and Thomas Schwetz.

Thank You!!SANDHYA CHOUBEY WHAT CAN WE LEARN FROM ATMOSPHERIC NEUTRINOS Neutrino 2006, 16.06.06 – p.41/41

Documents

Sandhya Choubey Harish-Chandra Research Institute ...lss.fnal.gov/conf/C0606131/6.2Choubey.pdf · WHAT WE CAN LEARN FROM ATMOSPHERIC NEUTRINOS Sandhya Choubey Harish-Chandra Research