Km3net: the Next Generation Neutrino Detectors

KM3NeT: The next generation neutrino detectors.

Kostas Pikounis on behalf of the KM3NeT Collaboration HEP 2019, NCSR "DEMOKRITOS", Athens, Greece 18/4/2019 Neutrino Astronomy

Neutrinos: • Expected to be produced in astrophysical objects where hadrons are accelerated v • Travel through universe in straight lines (not deflected by magnetic fields) ➢They can point back to their sources • Practically not absorbed by interstellar medium.

18/4/2019 2 Beakthrough in Neutrino Astronomy IceCube detected a trough-going muon with Energy ~24 TeV

Originating from a neutrino with Ev~ 300 TeV

Alert to telescopes IceCube-170922A Event

Blazar TXS 0506+056 in flaring state

~3σ coincidence

Proven hadronic activity

18/4/2019 3 Neutrino Mass Ordering normal ordering (NO) inverted ordering (IO) Determination of Neutrino Mass Ordering: a measurement of fundamental importance to the theory Using atmospheric neutrinos

➢ “Free beam” of known composition of νμ and νe ➢ Maximum difference between NO and IO due to matter effects for neutrinos traversing the earth o with zenith (θ) ~130 and Εν ~7 GeV ➢ Precise measurement of θ and Εν (GeV scale) treatment of systematics is important

νμ NO

νe IO

18/4/2019 K. Pikounis HEP 2019 4 KM3NeT collaboration

Oscillation Astroparticle Research with Research with Cosmics in the Cosmics in the Abyss (ORCA) Abyss (ARCA)

High energy Neutrino mass neutrino ordering astrophysics

Distributed large scale infrastructure housing the next 52 institutes generation neutrino detectors in the depths of the 16 countries Mediterranean Sea. 3 continents

18/4/2019 K. Pikounis HEP 2019 5 KM3NeT Scientific Objectives

Study the oscillations of “low Measurement of the diffuse Oscillation energy” atmospheric neutrinos high energy neutrino Astroparticle Research with astrophysical flux Research with Cosmics in the Cosmics in the Abyss (ORCA) ντ appearance from atmospheric Abyss (ARCA) neutrino oscillations Point source searches

High energy Neutrino mass Neutrinos from SN GRBs neutrino ordering astrophysics

Earth tomography ντ and flavor composition

Multi messenger synergies CR studies DM Earth and Sea sciences

18/4/2019 K. Pikounis HEP 2019 6 Detection principle

Neutrino interactions Neutrinos are detected with matter produce indirectly. secondary particles

• Relativistic charged particles produce Cherenkov light in water • Light is detected by arrays of photomultipliers (PMTs) • The interaction vertex and the muon/shower directions are reconstructed using the PMT position and the photon arrival times • Two major topologies: muonic tracks and cascades

18/4/2019 K. Pikounis HEP 2019 7 Event Topologies

Neutrino interactions with matter produce secondary particles

Track event topology: Cascade event topology: →Linear →spherical

(νμ) νμ CC (νഥe) νe CC atmospheric muons All ν NC

18/4/2019 K. Pikounis HEP 2019 8 Light in the Abyss Atmospheric muons and neutrinos: Astrophysical neutrinos:

Optical Noise (40K decays) : Bioluminescence:

18/4/2019 K. Pikounis HEP 2019 9 The KM3NeT DOM

The Multi – PMT DOM: Contains: • 31 3’ PMTs • All front-end and digitization electronics • Slow control sensors • Supporting mechanics

Provides: • Directional information • Isotropic ~ 4π field of view • Large photocathode area • Photocounting – high noise rejection already at DOM level

18/4/2019 K. Pikounis HEP 2019 10 KM3NeT/Detection Unit (DU)

Detection Unit: • Buoy Deployment with LOM: • 18 DOMs • Easy deployment of DUs • 2 Dyneema ropes (mechanical • Easy recovery of the LOM support). • Allows for deploying • VEOC (vertical electrical optical multiple DUs per sea cable) campaign • Different vertical spacing for ARCA / ORCA DUs

18/4/2019 K. Pikounis HEP 2019 11 ARCA and ORCA detectors

ORCA Building block: ARCA Building block: DOM spacing: ~9m DOM spacing: ~36m DU spacing: ~23m DU spacing: ~90m Albatross Depth: ~2450 m Depth: ~3500 m

ANTARES cable Building block: 115 DUs 18 DOMs / DU

18/4/2019 K. Pikounis HEP 2019 12 ARCA expected performance KM3NeT DOM & water properties → excellent angular resolution

Track events: Shower events:

Angular resolution: Angular resolution: ο ο 90% interval 90% interval < 0.2 Εν ≥ 10TeV < 2 Εν ≥ 60TeV median ο < 0.1 Εν ≥ 100TeV median 68% interval ν → μ angle 68% interval

Energy resolution: Energy resolution: 20% in log10(Eμ) 5% Εν ≥ 60TeV

18/4/2019 K. Pikounis HEP 2019 Plots for ν13e CC events ARCA: Field of view

complementarity with IceCube

IceCube KM3NeT

18/4/2019 K. Pikounis HEP 2019 14 ARCA expectations: Point Sources Using upgoing track events

Sensitivity for Vela X: Different scenarios for the percentage of the emission due to hadronic component Discovery Potential and Sensitivity flux normalization factor

18/4/2019 K. Pikounis HEP 2019 15 ARCA expectations: Point Sources

Point source with an E-2 unbroken power law energy spectrum

Using Using upgoing cascade track events events

5σ discovery flux for KM3NeT/ARCA (6 years)

Upgoing track events: Better sensitivity Better discovery potential Cascade events: Full sky coverage

18/4/2019 K. Pikounis HEP 2019 16 ARCA expectations: Diffuse flux with HESE

Ε −2.5 Using the high energy diffuse neutrino flux: Φ = 2.3٠10-18 휈 GeV-1٠cm-2٠s-1٠sr-1 • ν 100 TeV

• Using High Energy Starting Events • 5σ discovery of the astrophysical flux: 50% probability < 0.5 years 90% probability < 0.8 years! • Final shower sample: • Signal: 94% correctly identified • Background: ~12% contamination of atmospheric muon events • Final track sample: • Signal: 92% correctly identified • Background: ~7% contamination of atmospheric muon events

18/4/2019 K. Pikounis HEP 2019 17 ORCA expected performance

KM3NeT DOM & water properties → excellent angular resolution

Zenith angle resolution ~5o at 10 GeV Energy resolution ~25% at 10 GeV

18/4/2019 K. Pikounis HEP 2019 18 ORCA expectations: Mass Ordering

To determine the (NIO-NNO)/NNO (NIO-NNO)/NNO sensitivity to the 훎 νμ + 훎훍 neutrino mass νμ + 훍 ordering: • Gather enough statistics of νμ + νμ and νe + νഥe • Energy-zenith angle distributions: ORCA E,θ differences expected due resolutions to NO and IO. νe + 훎퐞 νe + 훎퐞

18/4/2019 K. Pikounis HEP 2019 19 ORCA expectations: Mass Ordering

To determine the sensitivity to the neutrino mass ordering: • Gather enough statistics of νμ + νμ and νe + νഥe • Energy-zenith angle distributions: differences expected due to NO and IO. • High discrimination power for track and shower events

18/4/2019 K. Pikounis HEP 2019 20 ORCA expectations: Mass Ordering

18/4/2019 K. Pikounis HEP 2019 22 ORCA expectations: ντ appearance

ντ channel is the least constrained.

Appearance of ντ due to oscillations of atmospheric νμ.

• Low energy ντ interactions mainly exhibit a cascade-like topology. • In 1 year of livetime expect:

~ 3k upgoing selected ντ events ~ 36k upgoing selected events • 5σ exclusion of non appearance after 2 months • 20% constraint at 3σ on tau normalization after one year

18/4/2019 K. Pikounis HEP 2019 22 Protvino to ORCA: P2O

• Proposal for collaboration between Protvino accelerator facility (Moscow) and ORCA detector. • Protvino accelerator →neutrino beam ORCA → far detector. • Baseline: 2595 Km • Target energy range : 3-8 GeV Image and plots from P2O LOI

18/4/2019 K. Pikounis HEP 2019 23 KM3NeT: Multi messenger program Alerts: • Online reconstruction • Dedicated triggers for events of interest • Distribute alerts via the GCN network • The optimization of the dedicated trigger for Galactic CTA Core Collapse Super Novae has already begun LIGO/VIRGO

SWIFT / SVOM

KM3NeT TAROT LSST ELT • Follow up EM / GW alerts • Offline correlation with catalogs (GRBs, AGNs, XRBs, SNs, FRBs, …) • Synergies and MoUs are in the process of being formed. K. Pikounis HEP 2019 HAWC SKA 24 KM3NeT: Depth dependence

• Selecting hits from many PMTs in time coincidence • Reject optical noise from 40K • Select light emitted from muons

KM3NeT preliminary

Dominated Dominated by by noise light produced (40K decays) by muons

Combined data from the ARCA and the ORCA DUs

18/4/2019 K. Pikounis HEP 2019 25 KM3NeT: Neutrino Candidates

Apply selection requirements to Selecting purely upgoing events: reject misreconstructed • Reject downgoing atmospheric muons atmospheric muon events • Select neutrino candidate events

In 82 days of data taking Upgoing events: Data: 13 upgoing events MC atmospheric neutrinos: 8 expected MC atmospheric muons: 1 expected

18/4/2019 K. Pikounis HEP 2019 26 KM3NeT: Neutrino Candidates

Apply selection requirements to Selecting purely upgoing events: reject misreconstructed • Reject downgoing atmospheric muons atmospheric muon events • Select neutrino candidate events

Real upgoing event (neutrino candidate) as detected by the deployed DU of the ORCA detector

18/4/2019 K. Pikounis HEP 2019 26 KM3NeT: Neutrino Candidates

Apply selection requirements to Selecting purely upgoing events: reject misreconstructed • Reject downgoing atmospheric muons atmospheric muon events • Select neutrino candidate events

Talk by Anna Sinopoulou about ARCA/KM3NeT data on Friday 15:40!

18/4/2019 K. Pikounis HEP 2019 26 Outlook

ARCA telescope and ORCA detector are currently under construction!

At least 7 more DUs are scheduled to be deployed in 2019! Data from ARCA and ORCA DUs are being analyzed

The depths of the Mediterranean Sea are becoming the new landmark for neutrino astronomy & neutrino properties studies!

Stay tuned! www.km3net.org @km3net KM3NeTneutrino

18/4/2019 K. Pikounis HEP 2019 27 Thank you!

18/4/2019 K. Pikounis HEP 2019 29 Back up

18/4/2019 K. Pikounis HEP 2019 30 Vτ CC interaction topology

τ decays to: High energy events: Low energy events: μ with 17.4% probability Track topology Track / cascade e with 17.8% probability Cascade / double bang topology Cascade topology Hadronically with 64.8% probability

double bang topology Track topology

18/4/2019 Event from IceCube K. Pikounis HEP 2019 31 KM3NeT: Acoustic Positioning To achieve the expected results from both detectors the position of each DOM should be known with an * Measurements accuracy of a few tens cm. – Expected values (vertical string) • A system of acoustic transmitters and receivers is developed. • In ARCA: 1 acoustic emitter + 2 x 18 receivers inside the DOMs Although underdetermined system → Great results!

Median values, calculated every 5 minutes

Acoustic data can be used for also for earth and sea sciences and possibly as a testing ground for acoustic neutrino detection. 50 μs ~ 8 cm

18/4/2019 K. Pikounis HEP 2019 27