complementarity between current and future oscillation...

Sushant Raut

Complementarity between current and future

oscillation experiments

Sushant Raut

NuHorizons2018, Allahabad

IBS - Center for Theoretical Physics of the Universe, Daejeon, South Korea

NuHorizons 2018, Allahabad 21 February 2018

Sushant Raut

Standard three-flavour oscillation framework:

Three mixing angles, two independent mass-squared differences, one CP-violating phase

Neutrino Oscillations


Atmospheric + LBL Solar + reactor Reactor + LBL

Dm231 Dm2

21

February 2018

Sushant Raut

Known measurements


1708.01186: de Salas, Forero, Ternes, Tortola, Valle

February 2018

Sushant Raut

Known measurements


1708.01186: de Salas, Forero, Ternes, Tortola, Valle

NH or IH?

LO or HO?

dCP=?

February 2018

Sushant Raut

Beyond standard oscillations

NuHorizons2018, Allahabad February 2018

Charged-current non-standard interactions (Production/detection NSIs): Additional 9+9 amplitudes, 9+9 phases

Neutral-current non-standard interactions (Propagation NSIs): Additional 6 amplitudes, 3 phases

Sterile neutrinos: Additional 3 angles, 2 phases, 1 mass-squared difference

Non-unitary mixing: Additional 9 amplitudes, 9 phases

Neutrino decoherence, neutrino decay, extra dimensions, new gauge interactions...

Sushant Raut

Measuring the unknowns


22 2 2

13 12 2

13 12 23

2 2 2 2

21 31

2

2

2 2

23 23

31 31

ˆsin ( )4sin sin 2

ˆ

2 sin sin 2 si

ˆsin ((1 ) )

ˆ(1 )

ˆ

sin cos

ˆsin((1 ) ) sin( )

ˆ ˆ(1n 2 cos( )

ˆwhere = / , / 4 , /

)CP

e

AP

A

m m m L

A

A

E A

A

m

A A

A

A

d

D

D DD

D

D D D D D

Measurements of the mass hierarchy, octant of 23 and dCP are affected by parameter degeneracies

February 2018

Sushant Raut

Parameter degeneracies:

Pe(NH, dCP) = Pe(IH, dCP’) ; P(23) = P(90-23)

Why do we not know what we don’t know?


See, for example: 1504.06283: Ghosh, Ghoshal, Goswami, Nath, SR 1406.2551: Coloma, Minakata, Parke

February 2018

Sushant Raut

Degeneracies in neutrino parameter space


dCP

0o

90o

270o

180o

February 2018

Sushant Raut NuHorizons2018, Allahabad

dCP

0o

90o

270o

180o


February 2018


dCP

0o

90o

270o

180o

Dm231>0

dCP

0o

90o

270o

180o Dm231<0


February 2018


dCP

0o

90o

270o

180o

Dm231>0

dCP

0o

90o

270o

180o Dm231<0

NH, LO = IH, HO


February 2018


dCP

0o

90o

270o

180o

Dm231>0

dCP

0o

90o

270o

180o Dm231<0

NH, LO = IH, HO NH, UHP = IH, LHP


February 2018


dCP

0o

90o

270o

180o

Dm231>0

dCP

0o

90o

270o

180o Dm231<0

NH, LO = IH, HO NH, UHP = IH, LHP No degeneracy


February 2018


dCP

0o

90o

270o

180o

Dm231>0

dCP

0o

90o

270o

180o Dm231<0

NH, HO = IH, LO NH, UHP = IH, LHP No degeneracy

Degeneracies in antineutrino parameter space

February 2018

Sushant Raut

Summary of degeneracies


Neutrinos Antineutrinos

February 2018

Sushant Raut




0. If the best-fit value is in the ‘green’ area, we are lucky 1. If we end up in the yellow unshaded area, lift the octant

degeneracy by collecting data with the opposite polarity 2. If we are in the shaded area, we need to resolve the

hierarchy degeneracy. This can only be done in conjunction with another experiment that measures dCP or is insensitive to dCP .

February 2018

Sushant Raut




0. If the best-fit value is in the ‘green’ area, we are lucky 1. If we end up in the yellow unshaded area, lift the octant

degeneracy by collecting data with the opposite polarity 2. If we are in the shaded area, we need to resolve the

hierarchy degeneracy. This can only be done in conjunction with another experiment that measures dCP or is insensitive to dCP .

current best-fit

February 2018

Sushant Raut

Different experiments have different L,E dependence, therefore their functional dependence on a given parameter p is different.

Synergies between experiments


two degenerate values for expt 1


February 2018

Sushant Raut

Different experiments have different L,E dependence, therefore their functional dependence on a given parameter p is different.

Synergies between experiments




true solution

February 2018

Sushant Raut

Combined c2 much higher than sum of the individual c2 : Synergy!


1308.5979: Ghosh, Ghoshal, Goswami, SR

February 2018

Sushant Raut

Current + future experiments


deca

y a

tmos

pheric

react

or

supe

rbeam

February 2018

DUNE ESSnSB

MOMENT DAR

JUNO

PINGU

HK ICAL@INO

T2HK

T2HKK

<~20 km 200-2000 km 20-200 km O(1000-10000 km)

T2K NOvA

Daya Bay D-Chooz

RENO

SK IceCube

Sushant Raut

Matter effects help to break the hierarchy-CP degeneracy

Mass hierarchy


22 2 2

13 12 2

13 12 23

2 2 2 2

21 31

2

2

2 2

23 23

31 31

ˆsin ( )4sin sin 2

ˆ

2 sin sin 2 si

ˆsin ((1 ) )

ˆ(1 )

ˆ

sin cos

ˆsin((1 ) ) sin( )

ˆ ˆ(1n 2 cos( )

ˆwhere = / , / 4 , /

)CP

e

AP

A

m m m L

A

A

E A

A

m

A A

A

A

d

D

D DD

D

D D D D D

February 2018

Sushant Raut

Mass hierarchy


For favourable combinations of parameters, NOvA and T2K can determine the hierarchy very well

1208.3644: Agarwalla, Prakash, SR, Uma Sankar

February 2018

For unfavourable combinations, we need to disentangle hierarchy and CP. For this we need data from an experiment that is either (a) insensitive to CP, (b) has more matter effects to break

the degeneracy, or (c) has negligible matter effects in

order to measure CP independently of the hierarchy

Sushant Raut

Mass hierarchy


Additional data from an experiment that is (a) insensitive to CP

1212.1305: Choubey, Ghosh, Thakore

Also see 1203.3388: Blennow, Schwetz

1305.5539: Winter

February 2018

Sushant Raut

Mass hierarchy


1307.2519: Barger et al.

DUNE

February 2018

Additional data from an experiment that (b) has more matter effects to break the degeneracy

Sushant Raut

Mass hierarchy



DUNE

February 2018

Additional data from an experiment that (b) has more matter effects to break the degeneracy

1704.06116: Agarwalla, Ghosh, SR

or (c) has negligible matter effects in order to measure CP independently of the hierarchy

Sushant Raut

Mass hierarchy


1611.06118: Abe et al.

T2HKK

T2HKK = T2HK (JD) + T2Kor (KD)

L = 295 km E = 0.6 GeV

L = 1100 km E = 0.6 GeV

Sushant Raut

Mass hierarchy


1508.07166 (JUNO CDR)

February 2018

2 2 2 2

31 12 21sineem m mD D D

Effective mass-squared difference relevant for electron neutrino disappearance experiments

2 2 2 2

31 31 12 212sinIH NH

m m mD D D

JUNO

Sushant Raut

CP violation


Hint from T2K, NOvA and SK for dCP around -90o

Favourable part of the parameter space if the hierarchy is normal

February 2018

Sushant Raut

CP violation


Synergy between NOvA and T2K helps constrain the wrong-hierarchy solution

Atmospheric neutrino expts which are typically insensitive to CP, can also improve CP measurement further by eliminating the wrong-hierarchy solution

1504.06283: Ghosh, Ghoshal, Goswami, Nath, SR

February 2018

Sushant Raut

CP violation


DUNE + NOvA + T2K + atmos

T2HK/T2HKK

1412.1744: Ghosh, Goswami, SR

1611.06118: Abe et al.

1703.07136: SR

T2HKK + DUNE

February 2018

Sushant Raut

CP violation


1406.2219: Agarwalla, Choubey, Prakash

ESSnSB ˆ 0lim sin sin( )

e

AC

CP

P

dP

d

dd

D D D

CP sensitivity is greater at the second oscillation maximum (D=3p/2) than at the first one (D=p/2)

February 2018

Sushant Raut

CP violation


1511.02859: Blennow, Coloma, Fernandez-Martinez

February 2018

Sushant Raut

CP violation




Combination of neutrino and antineutrino data helps in measuring dCP by breaking the degeneracy

February 2018

Sushant Raut

CP violation




Combination of neutrino and antineutrino data helps in measuring dCP by breaking the degeneracy

February 2018

1802.03677: Smirnov, Hu, Li, Ling

CPV at JUNO with new source of muons

Sushant Raut

Octant of 23


n disapp

dCP

23

Sushant Raut

Octant of 23


n disapp ne app

dCP

23

Sushant Raut

Octant of 23


Larger value of 13

n disapp ne app

dCP

23

n disapp ne app

dCP

23

Sushant Raut

Octant of 23


Synergy in octant measurement: Note the effect of reactor data (prior on 13)

1308.5979: Ghosh, Ghoshal, Goswami, SR

February 2018

Sushant Raut

Octant of 23


DUNE


February 2018

Sushant Raut

February 2018 NuHorizons2018, Allahabad

Octant of 23

1711.11107: Chakraborty, Deepthi, Goswami

T2HKK/T2HK/DUNE + current experiments

Sushant Raut

Beyond standard oscillation scenarios:

CC NSIs (production/detection),

NC NSIs (propagation),

Sterile neutrinos,

Non-unitarity, ...

Q1: How does the presence of new physics affect the measurement of the standard neutrino parameters?

Q2: Can the new physics parameters be measured?



Sushant Raut

Beyond standard oscillation scenarios:

CC NSIs (production/detection),

NC NSIs (propagation),

Sterile neutrinos,

Non-unitarity, ...

Q1: How does the presence of new physics affect the measurement of the standard neutrino parameters?

Q2: Can the new physics parameters be measured?



an opportunity to probe BSM physics!

February 2018

Sushant Raut

Sterile neutrinos


1605.04299: Agarwalla, Chatterjee, Palazzo

DUNE: Expansion of the parameter space leads to octant-dCP-d14 degeneracy

February 2018

Also see 1704.07269: Choubey, Dutta, Pramanik

1711.07464: Choubey, Dutta, Pramanik

Sushant Raut

Non-standard interactions


To probe CC NSIs (at source and detector) without interference from the NC NSIs (in propagation), use a low-energy experiment to reduce matter effects

Eg. ESSnuSB

Eg. MOMENT

1507.02868: Blennow, Choubey, Ohlsson, SR

1705.09500: Tang, Zhang

February 2018

NC NSIs (in propagation) are best probed with large matter effects

Eg. DUNE, T2HKK, atmospheric neutrino experiments


Degeneracies in measuring CPV at DUNE, T2HK and T2HKK

1612.01443: Liao, Marfatia, Whisnant

February 2018

Also see 1711.04840:Deepthi, Goswami, Nath

Sushant Raut

The presence of parameter degeneracies makes it difficult to measure the oscillation parameters unambiguously

These degeneracies can be lifted by a synergistic combination of experiments with different baselines, energies and channels

If Nature has chosen a favourable combination of the parameters, a measurement of the mass hierarchy, octant and CPV may be around the corner with T2K+NOvA+SK data

The next generation of experiments: DUNE, T2HK, T2HKK, ICAL@INO, etc will be able to determine the oscillation parameters accurately

Summary - 1


Sushant Raut

Matter effects play a crucial role in determining the mass hierarchy. Higher energy long-baseline and atmospheric neutrino data are useful in this regard

The synergy between reactor data and ne appearance helps to pinpoint the value of dCP

The synergy between reactor data , n disappearance and ne appearance (neutrino+antineutrino) helps to determine the octant of 23

In the case of new physics, many new degenerate solutions arise; new strategies will have to be devised to measure the parameters in such cases.

Summary - 2



THANK YOU

February 2018

Sushant Raut


complementarity between current and future oscillation...

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