KM3NeT

International Solvay Institutes

2729 May 2015, Brussels, Belgium.

Maarten de Jong

Astro-particle and Oscillations Research

with Cosmics in the Abyss

(ARCA & ORCA)

1

Introduction

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

2. Measurement of neutrino mass hierarchy

3. 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

2

Detection principle

muon 1 2 3 4 5

~ km

~ 100 m neutrino

interaction

time resolution 1 ns position resolution 10 cm

angular resolution 0.1 deg

3

KM3NeT

Architecture

shore station

remote access to data

remote operation on off

computer center

4

10100 Mb/s

neutrino telescope

Design ~

60

0 m

Optical module

Launcher vehicle

‒ 31 x 3” PMTs

‒ low-power HV

‒ LED & piezo inside

‒ FPGA readout

‒ White Rabbit

‒ DWDM

‒ rapid deployment

‒ autonomous unfurling

‒ recoverable 5

17”

Building block

6

RX

J17

13

eve

nts

/ y

ear

number of lines number of floors

Smallest detector with optimal efficiency ~ 1/6 total size

labs scaling factor labs scaling factor

ETEL

3-inch PMTs

Key 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

7

PDF of muon light

8

50 m

Dt [ns]

Angular resolution 0.1 degrees

1 T

eV m

uo

n PMT

Phased implementation

9

Phase Blocks Primary deliverables

1 0.2 Proof of feasibility and first science results;

2.0

2

ARCA

Measurement of neutrino signal reported by IceCube;

All flavor neutrino astronomy;

1

ORCA Neutrino mass hierarchy;

3 6 (+1) Neutrino astronomy including Galactic sources;

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

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

Prototyping

10

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

Rat

e [H

z]

Multiplicity

Rat

e [H

z]

PMT orientation

To be submitted Eur. Phys. J. C

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 11

Phase-1

12

ARCA

13

Measurement of neutrino signal reported by IceCube

~1 km ~1 km

1 building block 1 building block

PDF of shower light (I)

14

wave fro

nt

~ [m] log(E/TeV)

~ 100 m ne

time resolution 1 ns position resolution 10 cm

angular resolution ?

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

16

R2 [103 m2]

z [m

]

detector volume vertex cut

cosmic neutrinos atmospheric muons

R2 [103 m2]

80%

5.) Signal to Noise

17

“sweet spot”

5.) Signal to Noise

18 BDT (topology of event)

S e

ven

ts /

yea

r /

blo

ck

atmospheric muons atmospheric neutrinos (tracks) atmospheric neutrinos (showers) cosmic neutrinos (tracks) cosmic neutrinos (showers)

Sensitivity¶

19

observation time [y]

sign

ific

ance

[s

]

muon tracks 𝛉 ≥ 𝟖𝟎°

cascades cut & count

maximum likelihood

¶ Vetoing of atmospheric neutrinos not included.

F = 1.2 10−8 𝐸−2 𝑒−𝐸/(3 𝑃𝑒𝑉) 𝐺𝑒𝑉−1𝑠𝑟−1𝑠−1𝑐𝑚−2

Resolution

20

En [GeV] En [GeV]

Dq

[d

eg]

E R/E

T

Dq ER/ET

ne

KM3NeT/ARCA Preliminary KM3NeT/ARCA Preliminary

1 sigma

90%

Energy Direction

Simulation of 1.5 PeV nt event¶

21 ¶ Passes all cuts.

Diffuse muon analysis

22

sign

ific

ance

[s

]

observation time [y]

ORCA

23

Measurement of

neutrino mass hierarchy

200 m

1 building block

Neutrino mass hierarchy

24

mas

s

nt nm ne

“normal” “inverted”

109 eV

106 eV

103 eV

100 eV

10-3 eV

electron

proton

g

neutrino

1 : 1000,000,000,000

Neutrino mass hierarchy

25

oscillations

cross sections

fluxes

matter

L/E [km/GeV]

pro

bab

ility

E [GeV]

s [

10

-36 c

m2]

E [GeV]

EdN

/dE

[cm

-2 s

-1]

E [GeV]

probability

cos(

q)

ORCA

26

observation time [y]

sign

ific

ance

[s

]

¶ Using prior for q23 octant and dCP angle.

Future prospects (I)

27

~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

Future prospects (II)

28

RXJ1713¶

Vela X§

observation time [y]

sign

ific

ance

[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

29

sudden Eddy currents

Temperature

Earth & Sea sciences¶

France

observatory food supply

Bioluminescence

short lived (rare) events dominate life in deep-sea

permanent observatory

time profile ¶ Antares

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

30