Aart Heijboer

Exploring the Cosmoswith Neutrinosall of them.

vidi interview 14 mei 2008nm

Why look for High Energy Cosmic Neutrinos?To study the universe at high energies, neutrinos are the ideal messenger particle,not absorbed in the source or on their way to Earthnot deflected by magnetic fields: point back to the source

What is the physics of the most energetic objects in the universe? (Gamma Ray Bursts, Supernova remnants, Active Galactic Nuclei). What is the origin of high energy cosmic rays?

What is the nature of the Dark Matter?Big, open questions:

proton(cosmic ray)

How to detect Cosmic Neutrinos?Proposed research will be carried out with two European projects: ANTARES: uses 200x200x400 m3 of Mediterranean Sea water nearing completion. KM3NeT: will be at least 1x1x1 km3. In R&D phase.

Antares and its first neutrinos Upgoing muon detected (Atmospheric background) muon-neutrino

Neutrino flavour mixing Neutrinos come in three types (or flavours): nm, ne and nt

Observations of atmospheric and Solar neutrinos have showed that neutrinos have a tiny mass and change flavour.

Implication for neutrino telescopes: Even though the source produces (mostly) nm, on Earth all flavours are equally abundantntnmproposal:

Develop methods to detect ne and ntand use them to complement nm to maximizediscovery potential of Antares and KM3NeT

And use them to search for neutrinopoint sources.

ne

Event signaturesmuonnentelectronshower long track, not contained single localized 'shower' double bangtau leptondecays We will develop the data-analysis (reconstruction) software to exploit the information from all signatures.nm

Event signaturesmuonnentelectronshower long track, not contained single localized 'shower' double bangtau leptondecays We will develop the data-analysis (reconstruction) software to exploit the information from all signatures.nm double bangnm ne ntdirection resolution

energy resolution

detection rate

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ne and nt have low background and great energy resolutionenergy resolution is crucial to study the spectra which convey the physics of the sources.

Looking for point sourcesSky plot of one year of atmospheric muon neutrinosA neutrino sourceor a random clusterof atmospheric background neutrinos?

Looking for point sourcesA neutrino sourceor a random clusterof atmospheric background neutrinos?

Even a few ne and nt could resolve the question!Will develop the methods to classify events and combine them in a single events from different neutrino types

Summary Propose to exploit electron and tau neutrinos in addition to muon neutrinosNew capabilities will benefit experiments as a whole (opportunities to collaborate)Enhanced study of the source spectra & enable n-mixing measurements

My group will use these methods to perform the most sensitive search for cosmic sources of neutrinos with Antares Very high-profile measurementOptimal chance of discovering the first cosmic neutrino source!

Relevant experience: Developed search method and reconstruction currently used in ANTARES.Still well known (and occasionally active) flying start.Combining measurements & statistics: Bs-mixing at CDFOpening up new channels: Higgs search at CDF.Leadership, fruitful collaboration on large and small scales.

Now is the timeAntares will be completed in a few weeks!Crucial input needed soon to decide KM3NeT design.

Thank you for your attention.

Added power and science potentialEnergy resolution is crucial: background has know, very steep spectrum spectra convey the physics!

Tau Neutrino Signatures in IceCube: Overview

here, just about half the eventsare reconstructed as up going:=> reco is not doing anything useful(we're not even sure these events are muons at all... could be random k40)To very good approximation: true fraction of upgoing events is zero.Let's use this fact to our advantage for a change=> See how well reconstruction measures the number of up-going eventshere, (only) about 1% of events are reconstructedin wrong hemisphere.Is the muon reconstruction working?

5 string datawill discussthese later

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