KM3NeT The Birth of a Giant Vlad Popa, Institute for Space Sciences, Magurele-Bucharest, Romania

KM3NeTThe Birth of a Giant

Vlad Popa,

Institute for Space Sciences, Magurele-Bucharest, Romania

Overview

• Introduction: what, who and why?• Neutrino telescopes: how do they work?• Physics goals, but not only…• Present status, pilot experiments• Many choices to be made… • Conclusions

Overview


Overview


Overview


Overview


Overview


KM3NeT will be a very large volume (> km3 ) Neutrino Telescope, to be deployed in the Mediterranean Sea, after 2012.

Introduction


The consortium includes 40 Institutes or Universities from 10 European countries.

The research is financed trough 2 European projects: “KM3NeT-DS” (completed), “KM3NeT-PP”, and by national agencies

There will be room for Earth and Sea Sciences.

Introduction




There will be room for Earth and Ocean Sciences.

One of the Magnificent Seven of the ASPERA Roadmap

Introduction




There will be room for Earth and Ocean Sciences.

One of the Magnificent Seven of the ASPERA Roadmap

Introduction

Official web page: http://www.km3net.org

•Cyprus: University of Cyprus• France: CEA, CNRS, Haute Alsace University• Germany: Erlangen – Nurnberg University• Greece: Hellenic Open University, NCSR Demokritos, Athens National Observatory, Athens National University• Ireland: Advanced Study Institute, Dublin• Italy: INFN ( + Universities)• Netherlands: FOM (NIKHEF), NIOZ• Romania: ISS (INFLPR)• Spain: CSIC, Barcelona University, Valencia Technical University, Valencia University• United Kingdom: Aberdeen University, Leeds University, Sheffield University

Neutrino telescopes: how do they work?

Muon neutrinos (the “golden channel”):

XN

• Signature: muon (+ hadronic shower if reaction inside the detector)

• Detectability: if muon crosses light acceptance

• Measurement precision: Energy – fair (factor 2 at best for muon energies > 1TeV Direction – very good (0.1o at high energies)

• Remarks: the golden channel for point source searches (neutrino astronomy)

Electron neutrinos

XeNe

• Signature: electromagnetic + hadronic shower (superimposed)

• Detectability: if reaction is inside detector light acceptance

• Measurement precision: Energy – good Direction – fair (a few degrees at best)

• Remarks: Important for diffuse flux measurements and flavour studies. Not distinguishable from other shower signatures.

Tau neutrinos

XN • Signatures: 1) if like 2) if like 3) if : hadronic shower

• Detectability: if reaction is inside detector light acceptance (except 1)

• Measurement precision: Energy – fair (large fraction goes to secondary ’s) Direction – good for (1), fair otherwise

• Remarks: Important for diffuse flux measurements and flavour studies. Only double-bang signatures might be distinctive.

XN e XeNe hadrons

for E > few TeV “double bang sinature”

All neutrinos (neutral current interactions)

XN xx • Signatures: hadronic shower

• Detectability: if reaction is inside detector light acceptance

• Measurement precision: Energy – poor (large fraction goes to secondary ) Direction – fair

• Remarks: Important for diffuse flux measurements and flavour studies. Energy measurement much less precise, not distinguishable from other shower signatures.

Physics goals, but not only…

. Neutrino astronomy

• Diffuse neutrino flux

• Dark Matter

• Exotic Particles

• Atmospheric muons and neutrinos

• Neutrino Cross Sections

• …

• Earth and Sea Sciences

The main scientific goal: Neutrino Astronomy

• Point Sources• Supernova Remnants• Microquasars• Gamma Ray Bursters• Hidden Sources (not seen in other “wavelengths”)

Neutrino Astronomy: Sky coverage (Galactic coordinates)

From the South: IceCube(angular resolution~ 10 )

From the North:KM3NeT(angular resolution ~ 0.10)

> 75% of time>25% of time

Other physics goals


• Dark Matter




• …

Diffuse neutrino energy flux

Cosmogenic (extragalactic)

C.R. p (E > 1019.5 eV) / CMB (pions, HE neutrinos)

(GZK cutt-off)

From all GRB’s and AGN’s, during the complete Universe history, extragalactic for E > 1017 – 1018 eV

Other physics goals


• Dark Matter

Search based on WIMPS annihilation (in the center of the Sun) leading to HE neutrinos (directly in scenarios with extradimensions, or trough massive particle decays in supersymmetric scenarios).

Other physics goals


• Dark Matter




• …

• GUT Magnetic Monopoles

• Intermediate mass Magnetic Monopoles

• Nuclearites

•Q-balls

• …

Intermediate mass monopoles

GUT monopoles

Two categories

Magnetic charge g = n gD, n = 1,2,3,…? and gD= 137/2 e

Gauge theories of unified interactions predict MMs

Mass mM ≥ mX/G > 1016 GeV ~ 0.02 g 1017 GeV

SU(5)1015 GeV

10-35 sSU(3)C x [SU(2)L x U(1)y]

102 GeV

10-9 sSU(3)C x U(1)EM

Grand Unification: virtual X,Y

Electroweak unification: W, Z

Confinement region: virtual s, gluons, condensate of fermions -antifermion, 4 fermion virtual states

B=g/r2 Magnetic field of a point Dirac monopole

Radius (cm)10-29 10-16 10-13

r few fm B ~ g/r2

Size: extended object

Slowly moving!

Proton decay catalysis

Proton decay (Callan – Rubakov)

.........

)(

0

00

KMpM

eMpM

eMpM

227290

20 1010~17.0 cmwithc

A proton decay is expected every

10

10

2

9.5

9.5

H

H

nct

or

nL

Assuming Mon = 10-3, in water,

10 cm – 10m

30 s - 3 ms

GUT MMs detectable trough the Cherenkov light emitted by the proton decay charged secondaries, between 3 × 104 – 105 photons with = 300 – 600 nm for each event.

A trigger should require multiple coincidences in a relatively large time window, and the efficiency of such a search depends strongly on the assumed value of 0 and Mon…

Best existing flux limit from MACRO: 1121610 srscm

Intermediate mass MMs (105 - 1012 GeV)1994 De Rujula CERN-TH 7273/94

E. Huguet & P. Peter hep-ph/ 901370

T.W. Kephart, Q. Shafi Phys. Lett. B520(2001)313Wick et al. Astropart. Phys. 18, 663 (2003)

Produced in the Early Universe after GUT phase transitions

ex. (Shafi) M ~ 1010 GeV , g = 2 gD , no p-decay catalysis

IMMs can be accelerated in the galactic B field to relativistic

velocities

T = gD B L ~ 6 x 10 10 GeV (B/3x10-6 G) (L/300pc)

Galaxy T 6 x 1010 GeV

Neutron stars T 1011 - 1015 GeV

AGN T 1014 - 1015 GeV

Could they produce the highest energy cosmic ray showers E > 1020 eV ?

SO(10)1015 GeV

10-35 sSU(4) x SU(2) x SU(2)

109 GeV

10-23 sSU(3) x SU(2) x U(1)

Relativistic!

Intermediate mass MMs in VLVTs

74.01

n

74.0. MonCherenkov light production

- By the monopole (and by electrons) for

- By electrons for 51.0. Mon

Direct Cherenkov emission ( > 0.74)

22.

2

2

21

12

nng

dxd

Nd

MonD

Cherenkov emission enhanced by a factor about 8500 compared to Cherenkov light emission by a single muon

Cherenkov light from δ rays (knock-on electrons), Mon>0.51

2

max222 /1

1535.0T

TT

A

Z

e

g

dxdT

Nd D

222

11

2

ndxd

dN

e

Total number Cherenkov photons 300 < λ < 600 nm

Monopole•Direct• Recoil e-

Muon

•Aggregates of u, d, s quarks + electrons , ne= 2/3 nu –1/3 nd –

1/3 ns

•Ground state of QCD; stable for 300 < A < 1057

Produced in Early Universe or in strange star collisions (J. Madsen, PRD71

(2005) 014026)

Candidates for cold Dark Matter! Searched for in CR reaching the

Earth

R (fm) 102 103 104 105 106

M (GeV) 106 109 1012 1015 1018

A qualitative picture…

[black points are electrons]

N 3.5 x 1014 g cm-3

nuclei 1014 g cm-3

M (GeV)

1014 s e

du

u uu

u

dd

d s

ds

s s

e ee

- Essentially neutral (most if not all e- inside)- “Classical” properties: galactic velocities, elastic collisions, energy losses…- Could reach KM3NeT from above- Better flux limit from MACRO (for nonrelativistic velocities):

GeV10Mforsrscm102 1411216

M. Ambrosio et al., Eur.Phys. J. C13 (2000) 453; L. Patrizii, TAUP 2003

1010 Too low masses to reach KM3NeT

1022 Could traverse the Earth, but very low expected fluxes

Nuclearites - basics•Typical galactic velocities 10-3

• Dominant interaction: elastic collisions with atoms in the medium• Dominant energy losses:

• Phenomenological flux limit from the local density of DM:

A. De Rújula and S.L. Glashow, Nature 312 (1984) 734

)M/g1(8.7))sr2(yrkm( 112

)cloude(ng5.1Mcm10

)insidee()GeV104.8(ng5.1M4/M3216

143/2

2

.medv

dxdE

MDM 2/v

2

.medv

dxdE For M 8.4 1014 GeV it depends only on v2

The passage of a nuclearite in matter produces heat along its path

In transparent media some of the energy dissipated could appear as visible light (black body radiation)

The “optical efficiency” = the fraction of dE/dx appearing as light in water estimated to be = 3 10-5 (lower bound) (A. De Ruhula, S.L. Glashow, Nature 312 (1984) 734)

ev)L(v0

L

0

.meddx)x(

M

The velocity of a nuclearite entering in a medium with v0, after a path L becomes

in the atmosphere:

a = 1.2 10-3 g cm-3; b = 8.6 105 cm; H 50 km

(T. Shibata, Prog. Theor. Phys. 57 (1977) 882.)

in water: w 1 g cm-3

ea)x(atm

bxH

At ~ 4000 m depth, nuclearites with masses larger than ~1015 GeV should bestill fast enough to produce detectable black body light. Expected light yield >106 visible photons/cm!

Nuclearites could be seen by KM3NeT (as well as all other VLVnT’s) as correlated light hits distributed in a time window of ~ 10 ms.

Other possible exotic particles: Q-balls – nuggets of squarks and sleptons (“supersimetric nuclearites”…)

- neutral Q-balls would absorb normal hadrons emitting pions: their signature would be as for nuclearites, combined with the GUT monopole signals

- charged Q-balls would interact trough elastic collisions: would give nuclearite-like signals.

KM3NeT sensitivity to exotic particles (one year of data tacking) should be at the level of 10-18 cm-2 s-1 sr-

1 , depending on:

• The actual geometry of the telescope• The efficiency of the dedicated triggers• The efficiency of the off-line analysis (background removal, reconstruction strategy, etc.)

Intensive simulations to be made after the completion of the telescope design…

Other physics goals


• Dark Matter




Atmospheric muons and neutrinos

- More than 108 atm. muon (downward going) events expected each year: excellent callibration source, and CR primary composition from 10 TeV to 10 PeV

- About 100 000 atmospheric neutrino (upward going) events expected each year: very good statistics above 1 TeV, the tomography of the Earth interior possible, for E>10TeV.

Flavor analysis

From pion photo-production: 0:2:1:: e

At distances >> oscillation length: 1:1:1:: e

For atmospheric neutrinos with E > 1 TeV, oscillation effects become negligible.

Flavor ratio at H.E. will test neutrino production mechanisms, but also hypothesis about : - neutrino decays - neutrino oscillations into sterile states - CPT & Lorentz invariance violations ….

Other physics goals


• Dark Matter



• Neutrino Cross Sections: neutrino – nucleon interactions at very high energies (>> 200 GeV)

• …

Earth and sea sciences

- continuous data collection for long periods at “high” (~1Hz) rates. - water dynamics, bioluminiscence and bioacoustics as byproducts of the telescope itself. - geophysics and seismology, geotechnics, chemistry, bio-chemistry, oceanography, biology, fisheries, environmental sciences… from dedicated junction boxes.

KM3NeT will be part (node) of:

EMSO – European Multidisciplinary Seafloor Observatories

GMES – Global Monitoring for Environment and Security

Present status, pilot experiments

- KM3NeT – Design Study completed (FP6)- KM3NeT – Preparatory Phase ongoing (FP7, will end in 2012)

- Construction and deployment foreseen to start mid 2012 or beginning 2013

- Telescope fully operational in 2016?

KM3NeT takes advantage on the 3 pilot experiments

ANTARES

NEMO

NESTOR

All in the Mediterranean Sea

Most of the involved people are members of the KM3NeT


ANTARES

NEMO

NESTOR

This is why other neutrino telescopes (AMANDA, IceCUBE, Baikal, DUMAND) are not included in the list.


ANTARES

NEMO

NESTOR

-The only undersea neutrino telescope successfully deployed and tacking data

- Introducing and testing a different structure concept: the towers.

- First successful long term operation of a neutrino telescope floor at ~4000 m in 2003 .The star structure, and a new deployment strategy

- All have taught us that the marriage between neutrino physics and deep sea is not always a happy one…

Many choices to be made…

• The site

• The telescope “architecture”

• Legal aspects and governance• Power and data transfer• Shore infrastructure• Ships and ROV’s• Industrial production• Deployment / maintenance / decommissioning strategies• …

The site3 candidate locations, corresponding to the pilot

experiments• The depth. (Deeper is better? Not really!)• Water optical properties• Distance to the shore station• The bioluminescence• The 40K concentration• Current flow• Sediment flux• Shore infrastructure (ports, roads, airports…)• Cost effectiveness (including possible contributions from the local Governments)• Synergy with other undersea projects (GMES – Global Monitoring for Environment and Security, GOOS - Global Ocean Observing Systems, EuroGOOS, DEOS –Dynamics of Earth and Ocean System, EMSO – KM3NeT will be one of its nodes)• …





58

AUV Site Surveys*

Remus 6000 AUVDeepest site 5200 mNavigational accuracy app <

10 mHigh resolution MultibeamSide scan sonarImagerySub Bottom ProfilerEtc, etc

*) courtesy of IFM-Geomar, Kiel

Telescope architecture

Architecture: Optical Modules

• Single large (8”, 10”) PMTs?

Architecture: Optical Modules

• Many (31) small (~3”) PMTs?

Architecture: the detection units. “MEDUSA”

• ANTARES-like strings.

SOMMOM

SOM

Breakout

Architecture: the detection units “NuONE”

• NEMO-like towers.

8m

Architecture: the detection units. “SeaWiet”

Self-sustained OMs

Many strings might be deployed in the same operation

Decisions to be taken soon, based on intensive detector simulations and cost estimations

Common Layout91 Detector UnitsHexagon20 storeys per DU30m between storey

Compare configurationsDU spacing: 100, 130m, 160mfor each analysed configurations

Architecture: overall layouts

Homogeneous Cluster Ring …….

Conclusions…

Some KM3NeT-PP targets:

- Have the largest effective area at a given cost (250 M€)

- Deploy the telescope within 3 years

- Have an easily expandable facility

More information at: http://www.km3net.org

April 2008

KM3NeT

Technical Design Report

July 2009

Conclusions…

Documents

KM3NeT The Birth of a Giant Vlad Popa, Institute for Space Sciences, Magurele-Bucharest, Romania