Italy Pizza, Mozzarella di Buffala Switzerland Roesti, Cheese Fondue Netherland Stampot, Croquetten Spain Paella, Jamon

Italy Capri, Vesuvio, Pompei Switzerland Matterhorn Netherland Reichshaus, Grachten Spain Fallas,

Italy Calcio and Physics Switzerland Fussball and Physics Netherland Voetbal and Physics Spain Futbol and Physics

Italy OPERA Switzerland HERA Netherland ANTARES Spain

OPERA 2000-2001 Momentum measurement based on detection of multiple Coulomb scattering Emulsion Cloud Chamber: sandwiches of lead plates and nuclear emulsion sheets

HERA Member of H1 collaboration 2001-2005

Heavy Quarks Charm and beauty production in Neutral Current Motivation: experimental test of Standard Model and perturbativ QCD

Lifetime Distinguish heavy quarks from light quarks using variables sensitive to longer livetime

HERA:H1 Charm production in Charged Current Measurements of strange distribution

Neutrino Astrononomy Photons: Interact with CMB Protons: Deflect by magnetic fields (E<1019 eV Interact with CMB (E>1019 eV => <50 Mpc) Neutrinos: Unambiguous probe of hadronic processes Not deflected by magnetic fields -> point back to the source of emission Not absorbed by dust Horizon not limited by interaction with CMB Detectable over full energy range (GeV-PeV)

Sky Observable by Neutrino Telescope AMANDA/IceCube (South Pole) ANTARES/KM3 (North Hemispher)

Scientific scope Origin of cosmic rays Hadronic vs. leptonic signatures Limitation at low energies: Detector density Low light yield Limitation at high energies: Detector size Fast decreasing fluxes Supernova Oscillations Dark matter Astrophysical neutrinos ~MeV 10-100 GeV GeV-TeV TeV-EeV > EeV

How to measure neutrinos? Detection lines with PMTs Cherenkov light from muon Cheap high quality sea water Sea floor Muon Weak interaction Time and position from PMTs => muon trajectory Neutrino

What does ANTARES measure? 107 atmospheric muons per year 103 atmospheric neutrinos per year Detector Earth shielding rejects atmospheric muons upward going muon = neutrino-induced event ??? exotic neutrino per year 1019 ??? cosmic neutrino per year

How to measure neutrinos? Detection lines with PMTs Cherenkov light from muon Cheap high quality sea water Sea floor Muon Weak interaction Time and position from PMTs => muon trajectory Neutrino

What is ANTARES? In the Mediterranean Sea 2.1 km Installed off French coast 2.5 km under water 12 Lines (885 PMTs) Completed in May 2008 Data taking started soon after installation of the first line in 2006 2.1 km 2.5 km

Results and ongoing analysis Astroparticle Physics: Diffuse flux Point sources Neutrino oscillation Searches: Dark matter Multi messenger astronomy Magnetic monopoles/Nuclearites Particle physics: Atmospheric muon flux Cosmic rays anisotropy/composition Electromagnetic showers Detector related: Timing/positioning Water absorption length/refractive index Acoustic /

Muon energy loss Below 1 TeV: Continuous energy loss Above 1 TeV: Discrete energy loss Large energy fluctuation =>Electromagnetic showers

Phenomenology Cerenkov photons emitted: 1. Continuously along muon path 2. At Cerenkov angle 3. Arrive earlier than shower photons Shower photons emitted: 1. From one point 2. Almost isotropically 3. Arrive later than Cerenkov photons

Identification Method Simple Idea: 1. Reconstruct muon trajectory 2. Project photons onto muon track 3. Peak signals shower position

Photon emission position along MC muon track All reconstructed detected photons along the projected muon track Peaks selected by the algorithm Position of generated showers along the muon track

Algorithm Take muon direction Calculate photon emission (weight=1) Search shower candidate Eliminate background Fit 3-dimensional position Muons with shower multiplicity

Down going muon with two showers Result of muon recontruction Result of the 3D shower reconstruction Detected photon Peak=Shower position on muon track

Muon event rate as function of shower multiplicity MC shows: Shower energy 0.5TeV Muon energy with shower 3.7TeV Position resolution 10m Shower Efficiency 5% Shower Purity 70% Systematic errors from MC No reconstruction efficiency included

An application:

Cosmic Ray energies in Antares Primary energies measured by Antares between 10^13 eV and 10^16 eV (knee region included) Does the composition change at the knee region?

Pure proton primaries or pure iron primaries versus data No way to explain data with only proton or iron primaries

Fit MC templates from two different mass groups to data How much light nuclei (proton) and heavy nuclei (iron) do we need to reproduce data distribution? MC proton distribution = f_p(x) MC iron distribution = f_Fe(x) Data distribution = f(x) Fit data with this two MC templates (chi²-fit) f(x) = a * f_p(x) + b * f_Fe(x) Fit parameter: a, b

Light nuclei primaries or heavy nuclei primaries versus data Exclusive light nuclei primaries describe better the data than exclusive heavy nuclei primaries

Fit light and heavy nuclei to data High shower multiplicity dominated by heavy nuclei Low shower multiplicity domination by light nuclei Fit says data contains 91% light and 9% heavy nuclei

Conclusion Feasibility Goal: Distinguish light and heavy primary ray composition in different energy ranges Need: more statistics, energy estimator, independent variable (SRF,...) Composition measurements are hadronic interaction model dependent. How stable is the shower multiplicity method under different hadronic interaction models? (Chiariusi & Margiotta in Erlangen)

Backup sildes

OPERA Method

HERA

CC polarised cross sections No right handed CC