The High Energy Neutrino Sky as seen by Antares

Dorothea SamtlebenNIKHEF, Amsterdam

Halzen, F. & Klein,S.R. Review of Scientific Instruments 81, 081101, 2010

Extraterrestrial Neutrinos

Cosmic Neutrino Background

Particle Physics Dark Matter WIMPs accumulate in massive objects (Sun, Earth) => possibly annihilation signals observable,

Atmosphere acts as ‘beam dump‘ for cosmic rays => Studies for - Prompt production (high energies) - Neutrino oscillations (low energies)

Astrophysics

Neutrinos are valuable cosmic messengers coming undeflected from cosmic sources

Multimessenger approach exploited together with with detectors for electromagnetic radiation and gravitational waves

Neutrino sources

Microquasars Supernova remnantsGamma Ray Bursts

Highly energetic particle acceleration needed to explain observed cosmic ray energy spectrum

- g from inverse Compton scattering - g from synchrotron radiation of electrons - g from pion decay

Neutrino fluxes can be derived from g emission by assuming pion decay as origin of g

Xpp 0/ g

Xpp g/

gg

ee

SN1006Optical, radio, X-rays

Artist‘s viewArtist‘s view

Mediterranean Field of View

> 75%> 25%

2 downward sensitivity assumed

ANTARES Collaboration

CPPM, Marseille DSM/IRFU/CEA, Saclay APC, Paris LPC, Clermont-Ferrand IPHC, Strasbourg Univ. de H.-A., Mulhouse IFREMER, Toulon/Brest C.O.M. Marseille LAM, Marseille GeoAzur Villefranche INSU-Division Technique

University/INFN of Bari University/INFN of Bologna University/INFN of Catania LNS – Catania University/INFN of Pisa University/INFN of Rome University/INFN of Genova

IFIC, Valencia UPV, Valencia UPC, Barcelona

NIKHEF, Amsterdam Utrecht KVI Groningen NIOZ Texel

ITEP,Moscow Moscow State Univ

University of Erlangen• Bamberg Observatory

ISS, Bucarest

7 countries31 institutes~150 scientists+engineers

42°

interaction

Sea floor

Cherenkov light from

3D PMTarray

p

p, a

Cosmic rays interact with atmosphere => Showers, muons, neutrinos

Neutrinos arrive from astrophysical sources

Neutrino interaction in Earth => Muon passes detector

ANTARES detector

40 km toshore

• 12 lines mounted on the sea floor (2475m deep)• 25 storeys / line• 3 Photomultipliers / storey

PMTPMT

Track reconstruction

Track resolution0.43 0.10 deg in PS analysis

~105 atmospheric muons per day~5 atmospheric neutrinos per day

Quality important to eliminate misreconstructed muon tracks

Neutrino sky seen by Antares(galactic coordinates)

2007/8 analysis published (ApJ 743 L14 2011)

Update 2007-2010 data (813 days):

3048 neutrino candidates

Selected potential neutrino sources in red Most significant cluster,9 events within 3 degrees (2.2s)

Flux limit

5s 90% discovery potentialin comparison to IceCube 40for various different declinations => Sensitivity to different energy ranges

Study for 51 potential neutrino sources:

No significant excess => upper limits

Best limits for d<-30

Diffuse neutrino fluxData 2007-2009, corresponding to 335 active daysDistinction of diffuse flux from atmospheric neutrinos by energy (harder spectrum expected from sources)

Energy estimator R based on hit multiplicityon Photomultipliers

Simulation of energy estimator RDistribution of R in data in comparison to MC expectations

E-2 flux at limit

Prompt neutrinos (RPQM)

Diffuse neutrino flux

E2F(E)90%= 5.3 10-8 GeV cm-2 s-1 sr-1

20 TeV<E<2.5 PeV90% upper limit assuming E-2 flux spectrum

Search for Dark Matter

Dark Matter WIMPs accumulate in heavy objects (Sun)

Capture/Annihilation in equilibrium at the Sun core

Annihilation e.g. in bb/tt/WW -> +..

Model-independent event simulation using WIMPSIM

Interactions in the Sun and flavor oscillation, regeneration of t in the Sun taken into account

Background estimate from scrambled data

c

rc

<sv>

Distance to sun

Spin-independent cross-section limit for ANTARES 2007-2008 in CMSSM

Dark Matter limits from the sun

For CMSSM:Branching ratios = 1(for WW, bb, ττ)(Large variation ofbranching ratios overparameter space)

Compare SUSY predictions to observables as sparticles masses, collider observables, dark matter relic density, direct detection cross-sections, … SuperBayes (arXiv:1101.3296)

Dark Matter limits from the sunSpin-dependent cross-section limit for ANTARES 2007-2008 in CMSSM

For CMSSM:Branching ratios = 1(for WW, bb, ττ)(Large variation ofbranching ratios overparameter space)

Compare SUSY predictions to observables as sparticles masses, collider observables, dark matter relic density, direct detection cross-sections, … SuperBayes (arXiv:1101.3296)

Dark Matter limits from the sunSpin-dependent cross-section limit for ANTARES 2007-2008 in mUED

Compare mUED predictions to observables as KK masses, collider observables, relic density, direct detection cross-sections, … SuperBayes modified version (Physical Review D 83, 036008 (2011))

For mUEDTheoretical Branching ratios taken into account (no large variation over phase space)

Extra dimension:Dark Matter asKaluza Klein particles

Magnetic Monopole SearchMonopole with masses <1014 GeV can be accelerated to relativistic speeds and despite energy loss in Earth still leave visible signatures in neutrino telescopes

Light from Cerenkov radiation and below Cerenkov threshold via d electrons

Significantly more light yield than from muons

Limits for 0.625<b<0.995

from d electronsfor MM

Cerenkov from

CerenkovFrom MM

Photon yieldUpper Limits on the Flux

Neutrino oscillation

)cos16200(sin1

)27.1(sin1)(

2322

2322

Em

ELmP

• Low energy atmospheric neutrinos important

• Baseline L from zenith angle

• Energy estimate from track length

• Different track reconstruction using multi-line and single-line events (only zenith reconstructed)

Single LineMulti Line

Dashed: with oscillation

Simulation of reconstructed neutrinos

Measurement contours 1,2,3 s

Antares, K2K, Minos, SuperK

For maximal mixing

m2=(3.1±0.9) 10-3 eV2

DataBest FitNo oscillations

KM3NeT

First Funding already available to allowstart of construction

2012 Finalizing Design2013-15 Building/Deployment of first batch of detectors2015`++ Completion of Detector

Objective: Deep Sea Research Infrastructure in the Mediterranean Sea hosting a multi cubic kilometer neutrino telescope

Locations of the three pilot projects:ANTARES: ToulonNEMO: Capo PasseroNESTOR: Pylos

ConfigurationTDR , 180 m distances optimized for E-2 source spectrum

Average 180 m distances

IceCube

Average 130 m distances• Irregular pattern• Energy threshold

lower• More optimised for

Galactic sources

2400m

1750m

860m

Track resolution 0.1deg @ TeV5s discovery in 5 years of galactic sources feasible

New detector concept:Sphere with 31 PMTs

Technology of underwater neutrino telescope in seawater successfully proven with excellent angular resolution

Variety of physics analyses underway, first results published

Large several cubic kilometer array Km3NeT planned in the Mediterranean Sea, production of detectors is soon getting started

=> NEW WINDOW TO THE UNIVERSE AVAILABLE