observations of atmospheric neutrinos importance in particle and astroparticle physics ·...

Observations of Atmospheric Neutrinos Importance in Particle and Astroparticle Physics

Antoine Kouchner

University Paris 7 Diderot- AstroParticle and Cosmology

Multiple Messengers and Challenges in Astroparticle Physics” GSSI, october 6-17, 2014

Focus on: •  the Neutrino Mass Hierarchy •  Next Generation Detectors Biases toward: •  Cherenkov Techniques

Feel free to interrupt me!

Atmospheric Neutrino Connection

Cosmic-ray Induced particle physics

Particle physics Astroparticle

physics

Strong connection

Atmospheric neutrinos

Accelerator based

neutrino physics

Neutrino astronomy

I will focus on atmospheric neutrinos, but the link with particle physics and astroparticle physics is obvious through the detectors themselves. These detectors can also probe:

Nucleon decays Cosmic neutrinos Indirect search for dark matter

Accelerator neutrinos Monopoles …

2

Neutrinos 3

Introduction

Historical aspects

Atmospheric Neutrinos

The Atmospheric sector

Measuring the Neutrino Mass Hierarchy with Atmospheric Neutrinos

Current Knowledge on Neutrino Mixing

Phenomenological considerations

Detectors (mostly future project)

Water/Ice Cherenkov

Magnetized Trackers

Liquid Argon TPCs

High Energy Atmospheric Neutrinos

Spectrum measurement

Prompt component

Outline 4

Covered by T. Gaisser & F Halzen + WG discussion.

First atmospheric neutrinos

Physics Letters 18, (1965) 196, dated 15th Aug 1965 PRL 15, (1965), 429, dated 30th Aug. 1965

Kol

ar�G

old�F

ield

Eas

t R

and g

old m

ine

5

The first neutrino skymap?

Link to AstroParticle Physics

Link to Particle Physics

One of the main motivations: cross-section and mass of W propagator. Does the neutrino cross section saturate >1 GeV?

Mw

Predictions Halprin and Oakes 1978

6



Was the deficit due to oscillations? Or instrumental artifact?

7

Oscillation’s basic

Mixing in the

leptonic sector (θ)

Non-degenerate mass

spectrum (Δm2)

Oscillation Probability

P=ƒ(θ,Δm2)

Quantum interference

(macroscopic)

UPMNS matrix

(à la CKM)

⊕ ! =!

8

9

Experimental setup

P(Lo,ΔΕ)→ƒ(θ,Δm2)

theory!experiment!

rate & shape!(if resolution)!

rate only!

What is measured?

Source is far !  large statistics implies

large detectors

L not accurately known ! Not ultimate measurement

of Δm2

If Energy small ! Average measurement

9


~1 particle/(cm2 sec sr)

10

Flux predictions

"  P. Lipari, Introduction to Neutrino Physics

Rely on a mix of measurements and MC techniques. Many ingredients in the simulation:

µµ νννν+

+= eeR

Absolute neutrino flux 20-30% uncertainties

⇓ Measure Up/Down &

Up/down symmetry if No oscillation

No Earth magnetic field No relief

11

Flux predictions


Rely on mix of measurements and MC techniques. Many ingredients in the simulation:

pp cross section versus center of mass energy. Average number of charged hadrons produced in pp collisions versus center of mass energy

Link to Particle Physics Accelerator ! Recent LHC data

12

Flux predictions


Rely on mix of measurements and MC techniques. Many ingredients in the simulation:

•  high precision 3D calculations, •  refined geomagnetic cut-off treatment (also geomagnetic field in atmosphere) •  elevation models of the Earth •  different atmospheric profiles •  Detector’ environment (mountain)

13

Flux predictions

Remaining uncertainties ? Normalisation

Shape

INO site

"  M.S. Athar et al. arXiv:1210.5154

Honda et al. ICRC2007

WG discussion item?

14

Nucleon decay detectors !  At the beginning of the ’80s, some theories (GUT) predicted the proton

decay with measurable livetime

!  Detector size: 103 m3, and mass 1kt (=1031 p target)

!  The main background for the detection of proton decay were atmospheric neutrinos interacting inside the experiment

#  Water Cerenkov Experiments (IMB, Kamiokande) Kamioka Nucleon Decay Experiment Super-Kamioka Neutrino Detection Experiment #  Tracking calorimeters (NUSEX, Frejus, KGF) #  Result: NO proton decay ! (Some GUT ruled out) But some anomalies on the neutrino measurement!

15

Kamiokande results " Y. Fukuda et al., Phys. Lett. B335, 237 (1994).

4.5 kton detector

16

SuperKamiokande νµ

atmospheric ν results

GeV νatm & the imaging Cherenkov technique

Position & angular reconstruction

PID: separate νµ from νe

Record PMT charge and timing

µ

17

SK results 1998

The announcement of the discovery* of neutrino oscillation at Neutrino 98 by T. Kajita. * What about solar neutrinos?

" P

hys

.Rev

.Let

t.81:1

562-1

567,1

998

18

Consequences ? 19

!  Atmospheric Neutrino Oscillations ! we ‘see’ the oscillation

!  ! Credit to the oscillation solution to the solar anomaly

!  Dramatic consequences in astroparticle physics

!  MSW effect in the Sun, in Supernovae

!  Oscillation of cosmic neutrinos

!  But no Nobel Prize for oscillation

MACRO experiment Main features of Macro as ν detector

• Large acceptance (~10000 m2sr for an isotropic flux)

• Low downgoing µ rate (~10-6 of the surface rate )

• ~600 tons of liquid scintillator to measure T.O.F. (time resolution ~500psec)

• ~20000 m2 of streamer tubes (3cm cells) for tracking (angular resolution < 1° )

More details in Nucl. Inst. and Meth. A324 (1993) 337.

Data taking period: 1989 – 1994 construction 1994 – 2000 full

"Physics Letters B 434 1998. 451–457

20

SOUDAN II experiment

Soudan Mine Northern Minnesota 2100 mwe depth 963 t iron-tracking calorimeter Proportional counters veto shield •  Single track event with a dE/dX compatible with a muon ( νµ CC) •  Single shower events (νe CC)

224 calorimeter modules

νe νµ $

Ear

l A

Pet

erso

n –

Neu

trin

o 98

21

Situation circa 2002

End of the calorimetric tracking device (FREJUS, NUSEX) vs Cherenkov devices (SK, IMB) controversy. Further confirmation with Long BaseLine accelerator experiments. ! Exploring the atmospheric sector

22

LBL & the atmospheric sector det km GeV start

Japan KEK K2K SuperK 250 1.4 1999

Japan Tokai T2K SuperK 290 1.5 (on) 2009

US NuMI Soudan MINOS 730 17 2005

US NuMI Ash River NovA 810 2 (off) 2014

EU CERN GS Opera 732 17 2006

Sensitivity Δm2 > 10-3 eV2

23

Observation of tau neutrinos 24

SK: Evidence for appearance of τ neutrinos

" Phys. Rev. Lett. 110, 181802 (2013)

Signal: extra pions from tau decay ! More spherically symmetric ! Analysis based on Neural Network ! Maximum likelihood fit

Should allow for studies of ντ interaction physics with oscillation produced ντ

22,5 kt – 2806 days

25

Introduction

Historical aspects







Water/Ice Cherenkov

Magnetized Trackers

Liquid Argon TPCs



Prompt component

Outline 26


Massive neutrinos •  Neutrinos have distinct masses => why so light?

•  Often considered as first evidence of physics beyond the Standard Model. Are neutrinos fundamentally different from other particles? •  Neutrinos mix like quarks ⟹ why so similar/different?

Ue3 = sinθ13 e-iδ$UPMNS! UCKM!

27

Oscillations of Massive Neutrinos

Atmospheric θA~45°

Reactor θ13~9°

$%CP violating phase δCP

Solar θ&~30°

Majorana

28

All parameters measured to fair precision except: mass hierarchy octant of θ23

CP phase

Current Status of unknowns E. Li

si, La

rge

Neu

trin

o In

fras

truct

ure

, P

aris

, Ju

ne

2014

29

Why knowing the mass hierarchy? •  Help measuring the CP phase •  Absolute mass scale •  Nature (Dirac vs Majorana) •  Origin of neutrino mass and flavor •  Core-Collapse Supernovae Physics

Walter Winter Neutrino 2014

WG discussion item

Impact of direct mass ordering measurement

30

!  « Standard approach » :probe νµ νe governed by Δm231

!  Insensitive to the sign of Δm213 at leading order.

!  Matter effects (MSW) come to the rescue

!  Earth density variations (e.g. mantle-core) also affect the oscillations (parametric resonance)

[Neglecting solar (> a few GeV and >1000’s km) and CP violation effects]

Through matter, neutrinos interact acquiring an effective mass (forward scattering) Only electron neutrinos interact through CC with electrons !  Additional potential A in the Hamiltonian

m!m!

! Modify the oscillation probability

(�)+ for (anti-)neutrinos

MH with LBL experiments 31

Matter resonance: A ' Δ13cos2θ13 - Effective mixing maximal - Effective osc. frequency minimal

Resonance energy Earth: - Mantle Eres ~ 7 GeV - Core Eres ~ 3 GeV

Same signs

Opposite signs

Requirements: •  Δ13 ~ A matter potential must be significant but not overwhelming •  L large enough – matter effects are absent near the origin •  Distinction between neutrinos and anti-neutrinos

! different flux and cross-sections!

(Constant Density) Matter Effects 32

Phenomenological Summary

cosθ = �1 Inverted Hierachy

Normal Hierachy

In each case, CP-phase is varied in steps of 30 degrees

cosθ = �0.6

•  Hierarchy differences disappear at around 15 GeV

•  P(νµ!νe) < 2% at 20 GeV

GLoBES

GLoBES

P(νµ! νµ), NH

33

Phenomenological Summary

cosθ = �1 Inverted Hierachy

Normal Hierachy

In each case, CP-phase is varied in steps of 30 degrees

cosθ = �0.6

•  Hierarchy differences disappear at around 15 GeV

•  P(νµ!νe) < 2% at 20 GeV

GLoBES

GLoBES

Degeneracies due to parameter uncertainties must be carefully considered!

cosθ = �0.6

34

Muon versus Electron channels "  Agarwalla et al. arXiv:1212.2238

±10% Earth density

Muons provide more statistics Electron channel is more robust against detector resolutions… Brings additional sensitivity to the mass hierarchy Lately considered by PINGU and ORCA while main channel for HK

"  Honda et al. PRD 83:123001,2011

“Screening effect” r~2 & sin2θ23~0.5

But enhancement possible: - r increases with energy - Larger effect for second octant

35

Fluxes and cross sections

σ/Ε

(10

-38 G

eV-1

cm

-2)

! Use external measurements and regions without oscillations

Different cross sections for ν and ν !$ Three main contributions: Quasi-elastic, Resonant, DIS

σ (ν ) ≈ 2σ (ν )

cosθ = �0.6

φ x

E-2

(GeV

cm

-1 s

r-1 s

-1)

"  M.S. Athar et al. arXiv:1210.5154

Calculations now

made as a function of the position on Earth and the time

in year

x

"  Kajita, New J. Phys. 6 (2004) 194

x

A beam for free !

•  Produce neutrinos and anti-neutrinos •  Broad energy range: Steeply falling spectrum

!  Requires good energy resolution •  Broad path-length range

! Requires good direction resolution

36

WG discussion item

" Akhmedov et al. JHEP 02 (2013) 082 With exceedingly large PINGU effective volume

Uncorrelated systematics

S=45.5σ (f=0%) S=28.9σ (f=5%) S=18.8σ (f=10%)

In 5 years

Oscillograms & sensitivity for NT

Perfect resolutions

S=7.2σ (f=0%) S=4.5σ (f=5%) S=3.0σ (f=10%)

σE=4 GeV, σθ= 22.5°

37

Introduction

Historical aspects







Water/Ice Cherenkov

Magnetized Trackers

Liquid Argon TPCs



Prompt component

Outline 38


First achievements with Neutrino Telescopes

450 m

40 km Off Shore, French Riviera

12 line detector completed 2008

Oscillations maximal at 24 GeV for vertical neutrinos (muon range~120m) Larger effect on

low energy than

higher energy events

South Pole

IceCube (86 strings)+ DeepCore (8 strings)

Single lines

Multi lines

DeepCore

IceCube

" Phys. Lett. B 714 (2012) 22. " Phys. Rev. Lett. 111, 081801 (2013)

39

First achievements with Neutrino Telescopes

MC truth

2008-2010 data (863 days)

No oscill Oscill

IC79 data (319 days)

All results statistically limited

Other analyses have been recently presented

40

Latest results with DeepCore

J. Koskinen , NOW14

41

Latest results with DeepCore

IceCube now competes with SK and LBL experiments !

Great confidence for next steps

42

Proposed Low Energy Extensions

450 m

ORCA*

115 lines, 20m spaced, 18 OM/line 6m spaced

Instrumented volume ~3.8 Mt, 2070 OM

40 strings, 20-25m spaced, 96 OM/string 3m spaced

Instrumented volume ~ 6 Mt, 3840 OM

" S. Galata et al, VHEPU 2014 " A. Gross et al, ICRC13 proc 0555

PINGU#

Optimized layouts still under study

*First performances evaluated with a 50 string detector

43

31 3” PMTs " arXiv:1405.0839

#First performances evaluated 60 OMs/string

KM3NeT already taking data from an ANTARES line since April 2013

… and sees muons!

Coincidence in a DOM $

hits in different PMTs in a time window of 20ns

PMT down-looking PMT up-looking

Ncoinc θPMT (deg)

Events with Ncoinc>6 selected

PRELIMINARY PRELIMINARY

In situ tests of new Optical Module

" KM3NeT, arXiv:1405.0839

44

Event topologies

Track-like

Shower-like

45

Track-like contains both a cascade and one track

No track is identified

Not to scale

Preliminary performances (νµ)

450 m Water is a better tracker

Estimated with µ path length Should be improved

46

Preliminary performances (νe)

450 m

Water is a better tracker

47

Sensitivity studies To optimally distinguish between IH and NH: likelihood ratio test with nuisance parameters → deal with degeneracies by fitting!

LLR used to check FIM approach

1) fit mixing parameters assuming NH 2) fit mixing parameters assuming IH 3) compute ΔlogL = log( L(NH)/L(IH) ) θ23 , Δm2 and δCP can be fitted from data.

48

Current Sensitivities

Tracks Cascades

Combined

Quite similar results Both collaboration currently investigating details

Preliminary PiD included

49

Further on-going studies (  Reconstruction

“With the inelasticity, the total significance of establishing mass hierarchy may increase by

(20 - 50)%” "  Ribordy & Smirnov arXiv:1303.0758v1

Try to separate track-like (ν) to shower-like events (ν)

(  Atmospheric muons

Can use Veto from IceCube/Deepcore In addition to quality cuts

(  Inelasticity

Neutrinos Eν<20 GeV Muons (all energies)

No need for veto

Cut on reconstructed

vertex

Investigate sensitivity to Bjorken y

50

Studies of systematics

Earth Model Almost negligible impact

Atmospheric neutrinos flux •  Shape •  Normalization Large impact but normalization from data

Moderate impact

PMNS uncertainties

Several other studies point to the same conclusions e.g " W. Winter, Physical Review D, vol. 88, Issue 1, id. 013013 + PINGU LoI

" D. Franco et al, JHEP 04 (2013) 008

Method: extended unbinned log-likelihood ratio

Negligible impact varying combinations of {θ12, Δm221} (± 1σ)

Large impact varying combinations of {θ13, θ23, Δm231} (± 1σ)

Small impact varying CP phase

51

Project timelines Both project are subject to funding approval

Similar timelines

“Detector construction can be completed five years after funding starts, or as early as 2020.” “The PINGU share of the facility cost is roughly $55M (US cost, including contingency) plus $25M (foreign contribution) for a total of 80M$.” " arXiv:1409.5755v2 P5 report: “[…]cannot go forward as major projects at this time, due to concept maturity and/or program cost considerations. However, further development of PINGU is recommended […]” “…we encourage continued work to understand systematics. PINGU could play a very important role as part of a larger upgrade of IceCube, or as a separate upgrade, but more work is required.”

ORCA is part of the KM3NeT program A Possible scenario, subject to collaboration approval: Phase 1 (funded) : deploy a 6-7 string array In the ORCA configuration to demonstrate detection method in the GeV range. Phase 2 (40 M€) : deploy 1 building block 115 strings. Completion in 2019

52

Neutrino beam to PINGU/ORCA?

"  Lujan-Peschard et al, Eur. Phys. J. C (2013) 73:2439 ; Tang & Winter, JHEP 1202 (2012) 028

•  Muon counting experiment - Optimum 6-8 GeV 6000-8000 km but beam inclination

1 Mt mass

! 9 σ separation on purely statistical ground in one year

•  Electron counting experiment - Protvino-ORCA L=2588 km, beam inclined by 11.7° " J. Brunner, AHEP, Volume 2013 (2013), Article ID 782538.

1021 pot -- 3 years 7 σ stat. separation 3 σ with 3-4% sys

No need for

energy reconstruction

53

CP band 2nd octant

1st octant

NH

IH

CP band

Globes

Prospects with HyperKamiokande

Proposal for ~500 kT multi-purpose Water Cherenkov facility 295 km from JPARC and 8km off from SK. 1750 mwe overburden.

•  Well-known technology •  Sensitive to νe and νµ (and ντ )$•  Good control of systematics

Status: •  Among top priorities in Japan (with ILC) : 800 M$ estimated cost (without beam) •  If funded, access tunnel work should start in 2016 •  Excavation works in 2018 •  Detector operation in 2023

54

Prospect for the MH (atm)

After 10 years, determine MH at >3σ for values of sin2 θ23 > 0.4. Improved sensitivity is expected by adding beam data (>1σ sensitivity alone,

depending on δCP) ! >3σ in all cases.

Bands correspond to δCP range of

values NH IH

sin2 2θ13 =0.1 sin2 2θ13 =01

Ratio of oscillated νe rate over no oscillation case in sub-GeV and Multi-GeV channels. Statistical separation of νe and anti-νe.

" HK letter of Intent, arXiv:1109.3262v1

SK Sensitivity (σ)�

sin2θ23� now� +10 yrs�

0.4� 0.70� 0.98�

0.6� 1.50� 2.10 �

55

Prospects for θ23 octant and δCP

" From C. Walter, Neutrino Telescopes 2013

50% δCP fraction can be excluded at 3 σ after 10 yrs

Octant sensitivity 10 years of data

SK Sensitivity (σ)�

sin2θ23� now� +10 yrs�

0.4� 2.00 � 2.60�

0.6� 1.61� 2.10�

Bands correspond to δCP range of

values

With beam Atmospheric data

56

INO: India-based Neutrino Observatory

•  115 km west of Madurai (internat. airport) •  Pottipuram Village, Theni District, Tamil Nadu State •  1.9 km access tunnel •  Indian collab (~20 institutes) + Hawaii Univ (USA) •  Several other experiments when operational (ββ0ν, DM)

50 kton ICAL (room for additional 50kton)

1 km

Current Status: •  Fencing work started for facilities near portal and Madurai Center for HE Physics •  Waiting for full project approval by Indian Government

22

The INO-ICAL detector

[NB: Slightly different numbers exist]

Construction of RPC

Pickup strips

2 mm thick spacer

Glass plates Resistive coating on the outer surfaces of glass

2m x 2m glass RPC test stand

Cosmic –ray tracks are

seen…

Current Status: •  RPCs: help from Industry expected •  Electronics: ASIC (2nd batch being tested) and DAQ under development

•  Magnet: Prototype running at VECC Engineering module (800 ton) will be constructed by 2014.

23

Mass Hierarchy Discrimination

Further improvements expected by adding hadron events " arXiv:1306.1423v1

10 yrs 20 yrs

3σ$

INO + Other experiments "  Ghosh, Thakore & Choubey, arXiv:1212.1305 "  Blennow & Schwetz, JHEP 1208 (2012) 058,

Erratum-ibid. 1211 (2012) 098

Expected performances are a bit worse for IH

4σ$

10 yrs 20 yrs

INO only

INO + beams and reactors

24

The Liquid Ar TPC detectors

•  First achievements with ICARUS (760 tons at LNGS) ! Proof of technology. •  Excellent particle identification with low threshold (MeV)

•  Atmospheric neutrino studies •  Tau neutrino appearance •  Discrimination between νµ!ντ and νµ!νs

from upward/downward asymmetry " A. Stahl et al, LBNO, SPSC-EOI-007 (2012)

•  Proposed detectors (LBNO/E): staged approach up to 100 kton •  Sensitive to muons and electrons •  Hadronic component can me measured

70 m

20 m

25

Fiducial Exposure (kt-yrs)0 200 400 600 800

)2 χ∆√=

σSe

nsiti

vity

(

0

2

4

6 LAr Detector SimulationAtmospheric Neutrinos

Mass Hierarchy Determination

Normal HierarchyInverted Hierarchy

Input Parameters:π=CPδ=0.0242, 13θ2=0.4, sin23θ2sin

2eV-310×2.4±)=231m∆+2

32m∆1/2(

31

35 kt x 10 yrs = 350 kt-yrs

Mass hierarchy & octant with Lar TPCs

23θ2sin0.4 0.5 0.6

)2χ

∆√=σ

Sens

itivi

ty (

0

2

4

6

8Atmospheric Neutrinos

LAr Detector Simulation350 kt-yrs

σ3

Octant Determinationπ=CPδNormal Hierarchy,

=0CPδNormal Hierarchy, π=CPδInverted Hierarchy,

=0CPδInverted Hierarchy,

"LBNE arXiv:1307.7335

Requires very large detectors

Magnetized Lar TPCs ? => ~5σ (3σ ) with 250 kton.year exposure on MH (θ23) " V. Barger et al, Phys.Rev.Lett.109:091801,2012

Physics topics (with atmospheric ν) !  Current and future atmospheric detectors are also mentioned for:

!  Sensitivity to CP phase (Threshold <1GeV, MH known)

!  Earth tomography

!  Test NSI and other exotic physics

!  Sterile Neutrinos (Δm2 ~eV2 with TeV neutrinos)

"  Arman Esmaili, Alexei Yu. Smirnov, arXiv:1307.6824v1 "  Nunokawa et al, Phys.Lett. B562 (2003) 279-290

" Ohlsson et al, Phys. Rev. D 88 (2013) 013001 "  Gonzales-Garcia et al., Phys.Rev. D71 (2005) 093010

"  Gonzales-Garcia et al.,Phys.Rev.Lett.100:061802,2008, "  Agarwalla et al., arXiv:1212.2238v1

WG

dis

cuss

ion ite

ms

"  Razzaque & Smirnov, arXiv:1406.1407

HE neutrinos

Introduction

Historical aspects







Water/Ice Cherenkov

Magnetized Trackers

Liquid Argon TPCs



Prompt component

Outline 63



Low Energy High Energy

Conventional neutrinos dN/dE ~E-3.7

Pion/Kaon decay Mostly νµ$

Prompt neutrinos dN/dE ~E-2.7

Charm decay Isotropic ~Equal flavor

Atmospheric muon neutrino 2008-2011 data set Two different energy estimators: - dE/dX as evaluated from total collected charge - Combined likelihood for hit/no-hit for all OMs

L: length ε: efficiency

Atmospheric energy spectrum by unfolding measured spectrum averaged in 90°-180° zenith band

Ae = x A: response matrix E: true distribution

X: measured distribution )Good understanding of the detector

free param

" S. Adrian-Martinez et al., Eur. Phys. J.C (2013) 73:2006)

Atmospheric muon neutrino

"  M. G. Aartsen et al, arXiv:1409.4535 "  M.G. Aartsen, et al., Physical Review Letters 110 (15), 151105 (2013).

Prompt component to atmospheric spectrum

Several predictions exist + large theoretical uncertainties

Prompt neutrino contribution unknown but currently affecting astrophysical spectrum estimate (and viceversa)

Can Neutrino Telescopes probe Charm production? WG discussion item

Prompt component to atmospheric spectrum

Constraints from IceCube

J. Koskinen , NOW14

Summary (LE) !  Atmospheric Neutrinos have still a major role to play for precision measurements

and determination of unknown parameters such as the mass hierarchy and the search for exotic phenomena.

!  Proposed detectors include Iron Calorimeter, Liquid Argon and Cherenkov detectors. None of these projects being firmly funded.

!  Low energy (GeV) extensions of Neutrino Telescopes may be faster and cheaper than other alternatives…

!  …but challenging, as systematics must be carefully controlled. Key parameters are the size of the detector as well as the energy and angle resolutions.

!  Preliminary ORCA/PINGU sensitivities are quite promising.

!  Synergies/Combination with LBL/reactor experiments may provide the first high significance MH determination…

ORCA!

ORCA

But one should never trust a plot like this!

observations of atmospheric neutrinos importance in particle and astroparticle physics ·...

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