Decoherence in Neutrino Propagation through matter and bounds from - - PowerPoint PPT Presentation

Decoherence in Neutrino Propagation through matter and bounds from IceCube/DeepCore

PANE2018, ICTP, May 31, 2018

Hiroshi Nunokawa Department of Physics Pontifícia Universidade Católica do Rio de Janeiro

Based on Collaboration with Pilar Coloma, Jacobo Lopez-Pavan, Ivan Martinez-Soler, arXiv: 1803.04438 [hep-ph]

Outline

Introduction Conclusions Analysis Procedure Analysis Results Neutrino oscillation in matter with decoherence effect

Introduction

• So far, no convincing evidence/confirmation of

physics beyond the standard three neutrino flavor framework

• It is interesting to probe/constrain some new

physics beyond the standard framework

• It is important to test the paradigm of the

standard three flavor framework

• As one of the examples of such new physics, in

this talk, we consider (non-standard) quantum decoherence in neutrino oscillation

Introduction

• Neutrino oscillations occur due to quantum

interference separation of the wave packets

• “Coherence” is needed to that happen
• Oscillation is suppressed due to “decoherence”

effect, for example, by matter density fluctuation

• we consider non-standard decoherence effect

which may come from some new physics (which may be related to quantum gravity) assuming a phenomenological model finite energy and/or spatial resolution (uncertainty)

Introduction

Incomplete list of previous works on decoherence:

Lisi, Marrone, Montanitno, PRL 85, 1166 (2000) Fogli et. al., PRD 76, 0330066 (2007) Guzzo, Holanda, Oliveira, NPB908, 408 (2016) Coelho, Mann, Bashar, PRL118, 221801 (2017) Morgan et al., Astropart. Phys.25, 311 (2006) Benatti, Floreanini, JHEP 02, 032 (2000) Farzan, Schwetz, Smirnov, JHEP 07, 067 (2008) Bakhti, Farzan, Schwetz, JHEP 05, 007 (2015) Oliveira, Eur. Phys. J. C76, 417 (2016) Gago et al., PRD63, 073001 (2001) Carpio, Massoni, Gago, arXiv:1711.03690 [hep-ph] Gomes et al., arXiv:1805.09818 [hep-ph]

Quantum Decoherence: density matrix formalism H: Hamiltonian

describes decoherence

Hermicity (Lindbald form) Energy Conservation (or small enough to be neglected) (to avoid unitarity violation) assuming positivity

Neutrino propagation in uniform matter

where

: mixing matrix in matter

In a more familiar way,

: effective mass squared difference in matter

For constant matter density

: decoherence parameters (see next slide)

Assumptions on the Decoherence Parameters

Following the previous works, we assume power-law energy dependence

to have sizable effect of decoherence, we can roughly estimate that (but not enough condition)

For multi layers of constant matter densities For 1 layer of constant matter density

for 2 layers for 3 layers

3 layer approximation of the Earth matter density profile (mantle - core - mantle)

We consider the following 3 distinct cases (A) Atmospheric limit: ϒ21 = 0 (ϒ32 = ϒ31 ) (B) Solar limit I: ϒ32 = 0 (ϒ21 = ϒ31 ) (C) Solar limit II: ϒ31 = 0 (ϒ21 = ϒ32 )

10 100 E (GeV) 0.2 0.4 0.6 0.8 1 P(νµ→νµ) Normal ordering (A) γ31 = γ32 (B) γ21 = γ31 (C) γ21 = γ32 Standard Osc.

Some examples of oscillation probabilities

10 100 E (GeV) 0.2 0.4 0.6 0.8 1 P(νµ→νµ) Inverted ordering (A) γ31 = γ32 (B) γ21 = γ31 (C) γ21 = γ32 Standard Osc.

Some examples of oscillation probabilities

10 100 E (GeV) 0.2 0.4 0.6 0.8 1 P(νµ→νµ) Inverted ordering (A) γ31 = γ32 (B) γ21 = γ31 (C) γ21 = γ32 Standard Osc. 10 100 E (GeV)

0.2 0.4 0.6 0.8 1 P(νµ→νµ)

Normal ordering (A) γ31 = γ32 (B) γ21 = γ31 (C) γ21 = γ32 Standard Osc. 10 100 E (GeV) 0.2 0.4 0.6 0.8 1 P(νµ→νµ) Normal ordering (A) γ31 = γ32 (B) γ21 = γ31 (C) γ21 = γ32 Standard Osc. 10 100 E (GeV) 0.2 0.4 0.6 0.8 1 P(νµ→νµ) Inverted ordering (A) γ31 = γ32 (B) γ21 = γ31 (C) γ21 = γ32 Standard Osc.

Some examples of oscillation probabilities

We consider the following 3 distinct cases (A) Atmospheric limit: ϒ21 = 0 (ϒ32 = ϒ31 ) (B) Solar limit I: ϒ32 = 0 (ϒ21 = ϒ31 ) (C) Solar limit II: ϒ31 = 0 (ϒ21 = ϒ32 )

there are following approximated correspondences

NO of (A) IO of (C) NO of (B) IO of (A) NO of (C) IO of (B)

NO (IO): Normal (Inverted) mass Ordering

For higher energy (> 15 GeV) neutrinos,

for normal mass ordering for inverted mass ordering

To see the effect more globally 𝝃 oscillogram is useful

IceCube: Poissonian log-likelihood analysis

Analysis Procedure

DeepCore: Gaussian Maximum likelihood analysis For each analysis, simultaneous fit on the parameters of

was performed

Analysis Procedure

For IceCube, we consider the data presented in PhD thesis by B.J.P. Jones, available at http:/ /hdl.handle.net/1721.1/101327

from 400 GeV to 20 TeV , from cosθz= -1.02 to 0.24

Source of uncertainty Value Flux - normalization Free Flux - π/K ratio 10% Flux - energy dependence as (E/E0)η ∆η = 0.05 Flux - ¯ ν/ν 2.5% DOM efficiency 5% Photon scattering 10% Photon absorption 10% Table 1: The most relevant systematic errors used in our analysis of IceCube data,

systematic errors for IceCube data

200 400 600 800 Erec=[0.4, 0.6] TeV Erec=[0.6, 0.9] TeV 200 400 600 800 Erec=[0.9, 1.3] TeV Erec=[1.3, 1.9] TeV

• 1.0
• 0.8
• 0.6
• 0.4
• 0.2

0.0 200 400 600 800 cos(z

rec)

Erec=[1.9, 6.2] TeV

• 1.0
• 0.8
• 0.6
• 0.4
• 0.2

0.0 cos(z

rec)

Erec=[6.2, 20] TeV

Expected event distribution for IceCube with and w/o decoherence

IceCube Data: B.J.P .Jones, PhD thesis http://hdl.handle.net/1721.1/101327

Analysis Procedure

Analysis Procedure

For DeepCore we consider the data presented in Aartsen et al., PRL117, 071801 (2016) from ～10 GeV to ～1 TeV , 8 bins below cosθz= 0

systematic errors for DeepCore data

Source of uncertainty Value Flux - normalization Free Flux - energy dependence as (E/E0)η ∆η = 0.05 Flux - (νe + ¯ νe)/(νµ + ¯ νµ) ratio 20% Background - normalization Free DOM efficiency 10% Optical properties of the ice 1% Table 2: Systematic errors used in our analysis of DeepCore data, taken from

• refs. [44, 48].

50 100 150 200 Erec=[6, 8] GeV Erec=[8, 10] GeV 50 100 150 200 Erec=[10, 14] GeV Erec=[14, 18] GeV 50 100 150 200 Erec=[24, 32] GeV Erec=[24, 32] GeV

• 1.0
• 0.8
• 0.6
• 0.4
• 0.2

0.0 50 100 150 200 cos(z

rec)

Erec=[32, 42] GeV

• 1.0
• 0.8
• 0.6
• 0.4
• 0.2

0.0 cos(z

rec)

Erec=[42, 56] GeV

Expected event distribution for DeepCore with and w/o decoherence

DeepCore Data: IceCube Collab. PRL117, 071701 (2016)

Analysis Procedure

Bounds from IceCube and DeepCore

10-25 10-23 10-21 5 10 15 20 25 30

0(GeV) 2

SK(90% CL) KamLAND (21,95% CL)

ij=0

• ----32=21
• ----31=21
• ----31=32

95% CL 10-29 10-27 10-25 10-23 5 10 15 20 25 30

0(GeV) 2 ij=0(E/GeV)

• ----32=21
• ----31=21
• ----31=32

95% CL 10-34 10-32 10-30 10-28 10-26 10-24 5 10 15 20 25 30

0 (GeV) 2

SK (90% CL)

ij=0(E/GeV)2

• ----32=21

31=21 31=32

95% CL

p

solid curves: IC

dashed curves: DC

n = 0 n = 1 n = 2

• 2
• 1

1 2 10-32 10-29 10-26 10-23 10-20 10-17 n

0(GeV) =0(E/GeV)n

31=32 21=31 21=32

IceCube DeepCore

• 2
• 1

1 2 10-32 10-29 10-26 10-23 10-20 10-17 n

0(GeV) =0(E/GeV)n

31=32 21=31 21=32

IceCube DeepCore roughly,

Summary of Bounds we obtained

Normal Ordering n = −2 n = −1 n = 0 n = 1 n = 2 IceCube (this work) Atmospheric (γ31 = γ32) 2.8 · 10−18 4.2 · 10−21 4.0 · 10−24 1.0 · 10−27 1.0 · 10−31 Solar I (γ31 = γ21) 6.8 · 10−19 1.2 · 10−21 1.3 · 10−24 3.5 · 10−28 1.9 · 10−32 Solar II (γ32 = γ21) 5.2 · 10−19 9.2 · 10−22 9.7 · 10−25 2.4 · 10−28 9.0 · 10−33 DeepCore (this work) Atmospheric (γ31 = γ32) 4.3 · 10−20 2.0 · 10−21 8.2 · 10−23 3.0 · 10−24 1.1 · 10−25 Solar I (γ31 = γ21) 1.2 · 10−20 5.4 · 10−22 2.1 · 10−23 6.6 · 10−25 2.0 · 10−26 Solar II (γ32 = γ21) 7.5 · 10−21 3.5 · 10−22 1.4 · 10−23 4.2 · 10−25 1.1 · 10−26 Inverted Ordering IceCube (this work) Atmospheric (γ31 = γ32) 6.8 · 10−19 1.2 · 10−21 1.3 · 10−24 3.5 · 10−28 1.9 · 10−32 Solar I (γ31 = γ21) 5.2 · 10−19 9.2 · 10−22 9.8 · 10−25 2.4 · 10−28 9.0 · 10−33 Solar II (γ32 = γ21) 2.8 · 10−18 4.2 · 10−21 4.1 · 10−24 1.0 · 10−27 1.0 · 10−31 DeepCore (this work) Atmospheric (γ31 = γ32) 1.4 · 10−20 5.8 · 10−22 2.2 · 10−23 7.5 · 10−25 2.3 · 10−26 Solar I (γ31 = γ21) 8.3 · 10−21 3.6 · 10−22 1.4 · 10−23 4.7 · 10−25 1.3 · 10−26 Solar II (γ32 = γ21) 5.0 · 10−20 2.3 · 10−21 9.4 · 10−23 3.3 · 10−24 1.2 · 10−25 Previous Bounds SK (two families) [7] 2.4 · 10−21 4.2 · 10−23 1.1 · 10−27 MINOS (γ31, γ32) [32] 2.5 · 10−22 1.1 · 10−22 2 · 10−24 KamLAND (γ21) [15] 3.7 · 10−24 6.8 · 10−22 1.5 · 10−19

Summary of Bounds we obtained

Normal Ordering n = −2 n = −1 n = 0 n = 1 n = 2 IceCube (this work) Atmospheric (γ31 = γ32) 2.8 · 10−18 4.2 · 10−21 4.0 · 10−24 1.0 · 10−27 1.0 · 10−31 Solar I (γ31 = γ21) 6.8 · 10−19 1.2 · 10−21 1.3 · 10−24 3.5 · 10−28 1.9 · 10−32 Solar II (γ32 = γ21) 5.2 · 10−19 9.2 · 10−22 9.7 · 10−25 2.4 · 10−28 9.0 · 10−33 DeepCore (this work) Atmospheric (γ31 = γ32) 4.3 · 10−20 2.0 · 10−21 8.2 · 10−23 3.0 · 10−24 1.1 · 10−25 Solar I (γ31 = γ21) 1.2 · 10−20 5.4 · 10−22 2.1 · 10−23 6.6 · 10−25 2.0 · 10−26 Solar II (γ32 = γ21) 7.5 · 10−21 3.5 · 10−22 1.4 · 10−23 4.2 · 10−25 1.1 · 10−26 Inverted Ordering IceCube (this work) Atmospheric (γ31 = γ32) 6.8 · 10−19 1.2 · 10−21 1.3 · 10−24 3.5 · 10−28 1.9 · 10−32 Solar I (γ31 = γ21) 5.2 · 10−19 9.2 · 10−22 9.8 · 10−25 2.4 · 10−28 9.0 · 10−33 Solar II (γ32 = γ21) 2.8 · 10−18 4.2 · 10−21 4.1 · 10−24 1.0 · 10−27 1.0 · 10−31 DeepCore (this work) Atmospheric (γ31 = γ32) 1.4 · 10−20 5.8 · 10−22 2.2 · 10−23 7.5 · 10−25 2.3 · 10−26 Solar I (γ31 = γ21) 8.3 · 10−21 3.6 · 10−22 1.4 · 10−23 4.7 · 10−25 1.3 · 10−26 Solar II (γ32 = γ21) 5.0 · 10−20 2.3 · 10−21 9.4 · 10−23 3.3 · 10−24 1.2 · 10−25 Previous Bounds SK (two families) [7] 2.4 · 10−21 4.2 · 10−23 1.1 · 10−27 MINOS (γ31, γ32) [32] 2.5 · 10−22 1.1 · 10−22 2 · 10−24 KamLAND (γ21) [15] 3.7 · 10−24 6.8 · 10−22 1.5 · 10−19

(1) (2) (3) (4) (5) (6) ~(1) ~(2) ~(3) ~(4) ~(5) ~(6)

Conclusions

• We found that the bounds and/or sensitivities depend

strongly on the neutrino mass ordering and matter effect is important

• For neutrinos, the decoherence effect is mainly driven by

ϒ21 (ϒ31) for normal (inverted) mass ordering

• For antineutrinos, the decoherence effect is mainly driven

by ϒ32 (ϒ21) for normal (inverted) mass ordering

• We obtained better (improved) bounds for most of the

cases except for n = -1

• We revisit the quantum decoherence in the context

neutrino oscillation with full 3 flavor framework

• 3 flavor analysis is required to interpret correctly the

bounds on the decoherence parameters

Thank you very much for your attention!

backup slides

Neutrino propagation in non-uniform matter: adiabatic regime

after averaging out, finally we have

relevant for solar 8B neutrinos

cos 2˜ θ13 = cos 2θ13 a/∆m2

ee

p (cos 2θ13 a/∆m2

ee)2 + sin2 2θ13

, cos 2˜ θ12 = cos 2θ12 a0/∆m2

21

q (cos 2θ12 a0/∆m2

21)2 + sin2 2θ12 cos2(˜

θ13 θ13) , ∆ ˜ m2

21 = ∆m2 21

q (cos 2θ12 a0/∆m2

21)2 + sin2 2θ12 cos2(˜

θ13 θ13), ∆ ˜ m2

31 = ∆m2 31 + (a 3

2a0) + 1 2(∆ ˜ m2

21 ∆m2 21),

∆ ˜ m2

32 = ∆ ˜

m2

31 ∆ ˜

m2

21.

p

Denton, Minakata, Parke, arXiv:1801.06514 where

10-25 10-24 10-23 10-22 10-21 2 4 6 8 10

0(GeV) 2

SK(90% CL) KamLAND

(21,95% CL)

ij=0 32=21 31=21 31=32 21 31

95% CL

Results of More general analysis varying 2 decoherence parameters ϒ31 and ϒ21 freely