1

KM3NeT

International Solvay Institutes 2729 May 2015, Brussels, Belgium.

Maarten de Jong

Astro-particle and Oscillations Researchwith Cosmics in the Abyss

(ARCA & ORCA)

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Introduction

1. Discovery and subsequent observation ofhigh-energy neutrino sources in Universe

2. Measurement of neutrino mass hierarchy3. Synergy with Earth & Sea sciences

• KM3NeT is a new Research Infrastructure– network of cabled observatories– located in deep waters of Mediterranean Sea– hosting multi-km3 Neutrino Telescope

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Detection principle

muon

wave front1 2 3 4 5

~ km

~ 100 mneutrino

interaction

time resolution 1 nsposition resolution 10 cm angular resolution 0.1 deg

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KM3NeT

Architecture

shore station

remote accessto data

remoteoperationon off

computercenter

0.1

1 Tb/

s

10100 Mb/s

neutrino telescope

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Design~

600 m

Optical moduleLauncher vehicle

‒ 31 x 3” PMTs‒ low-power HV‒ LED & piezo inside‒ FPGA readout‒ White Rabbit‒ DWDM

‒ rapid deployment‒ autonomous unfurling‒ recoverable

17”

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ETEL

3-inch PMTsKey features:

– timing ≤ 2 ns (RMS)– QE ≥ 25-30%– collection efficiency ≥ 90%– photon counting purity 100% (by hits, up to 7)– price/cm2 ≤ 10” PMT

ETEL D792 Hamamatsu R12199 HZC XP53B20

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PDF of muon light

50 m

Dt [ns]

Angular resolution 0.1 degrees

1 Te

V m

uon

PMT

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Phased implementation

Phase Blocks Primary deliverables

1 0.2 Proof of feasibility and first science results;

2.0

2ARCA

Measurement of neutrino signal reported by IceCube;All flavor neutrino astronomy;

1ORCA

Neutrino mass hierarchy;

3 6 Neutrino astronomy including Galactic sources;

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1) Optical module deployed at Antares April 2013 (2500 m)

2) Mini string deployed at Capo Passero May 2014 (3500 m)

Prototyping

Eur. Phys. J. C (2014) 74:3056

Rate

[Hz]

Multiplicity

Rate

[Hz]

PMT orientation

To be submittedEur. Phys. J. C

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Phase-1

First string assembled end of last year

® to be deployed at KM3NeT-France following weeks• Completion Phase-1 by end 2016

– 24 strings in KM3NeT-Italy– 6 more strings à la ORCA in KM3NeT-France

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Phase-1

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ARCA

Measurement of neutrino signal reported by IceCube

~1 km ~1 km

1 building block 1 building block

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Cascade analysis 1.0 cut & count

1. Online data filter– 5 (or more) coincidences between PMTs in same optical module

(DT = 10 ns)

2. Event filter– number of hits ≥ 2000

3. Vertex cut– veto atmospheric muons

4. Energy cut– total time-over-threshold ≥ 12 ms

5. MRF/MDP cut– 2D cut based on Boosted Decision Tree & energy estimate

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3.) Atmospheric muon veto

R2 [103 m2]

z [m

]

detector volume vertex cut

cosmic neutrinos atmospheric muons

R2 [103 m2]

80%

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5.) Signal to Noise

“sweet spot”

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5.) Signal to Noise

BDT (topology of event)

S e

vent

s / y

ear /

blo

ck

atmospheric muonsatmospheric neutrinos (tracks)atmospheric neutrinos (showers)cosmic neutrinos (tracks)cosmic neutrinos (showers)

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Sensitivity¶

observation time [y]

sign

ifica

nce

[s]

muon tracks

cascadescut & count

maximum likelihood

¶ Vetoing of atmospheric neutrinos not included.

F

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Resolution

En [GeV] En [GeV]

Dq

[deg

]

E R/E T

DqER/ET

ne

KM3NeT/ARCA Preliminary KM3NeT/ARCA Preliminary

1 sigma90%

Energy Direction

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Simulation of 1.5 PeV nt event¶

¶ Passes all cuts.

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Diffuse muon analysissi

gnifi

canc

e [s

]

observation time [y]

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ORCA

Measurement of neutrino mass hierarchy

200 m

1 building block

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Neutrino mass hierarchy m

ass

ntnmne

“normal” “inverted”

109 eV

106 eV

103 eV

100 eV

10-3 eV

electron

proton

g

neutrino

1 : 1000,000,000,000

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Neutrino mass hierarchyoscillations

cross sections

fluxes

matterL/E [km/GeV]

prob

abili

ty

E [GeV]

s [1

0-36 c

m2 ]

E [GeV]

EdN

/dE

[cm

-2 s

-1]

E [GeV]

probabilityco

s(q

)

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ORCA

observation time [y]

sign

ifica

nce

[s]

¶ Using prior for q23 octant and dCP angle.

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Future prospects (I)

~1 km

1 building block

~1 km

1 building block

~1 km

1 building block

~1 km

1 building block

~1 km

1 building block

~1 km

1 building block

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Future prospects (II)

RXJ1713¶

Vela X§

observation time [y]

sign

ifica

nce

[s]

RXJ1713-3946

Vela X

¶ S.R. Kelner, et al., Phys. Rev. D 74 (2006) 034018. § F.L. Villante and F. Vissani, Phys. Rev. D 78 (2008) 103007.

(binned analysis)

Galactic sources

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suddenEddy currents

Temperature

Earth & Sea sciences¶

France

observatoryfood supply

Bioluminescence

short lived (rare) eventsdominate life in deep-sea

permanent observatory

time profile¶ Antares

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KM3NeT status & outlook• R&D

– developed cost-effective technology– feedback from prototypes confirm key specifications

• Phase-1– going ahead as planned

• Phase-2– ARCA

• measurement of IceCube flux with different methodology, complementary field of view and improved resolution

• all flavour neutrino astronomy

– ORCA• measurement of neutrino mass hierarchy

• Future prospects– exploration of our Galaxy