The Pierre Auger Project

Angela Olinto Cosmic Rays

1912 discovered by Victor Hess (after work of Wilson & others) Energy range: £ 109 eV to = 1020 eV direct detection up to 1014 eV & indirect det. above 1014 eV via: Extensive Air Showers (EAS) discovered by Pierre Auger, 1938 Spectrum:» featureless J ~ E-2.7, 108eV < E < 1015eV THE KNEE J ~ E-3, 1015eV < E < 1018eV Detectors: Ground Arrays scintillator /water-Cerenkov detectors (> 8km2): Volcano Ranch(US), Haverah Park(UK), SUGAR (Au), Yakutsk (Ru), AGASA(Jp) – 170 km 2 Fluorescence Detectors Fly’s Eye, High Resolution F.E. 1949 – E. Fermi – E < 1015eV SN shock acceleration Cosmic Ray Spectrum

Compilation by S. Swordy AGASA Surprise! Events with energies = 1020 eV EXIST!!!! Fly’s Eye record holder (10/91): 3.2 1020 eV AGASA (90-00): 8 events above 1020 eV & 728 events above 1019 eV HiRes Fly’sEye (99-00): 7? events > 1020 eV Haverah Park (1987): 4 events > 1020 eV Volcano Ranch (1962): 1 event > 1020 eV NO GZK cutoff!!! (Greisen-Zatsepin-Kuzmin ‘66) photo-pion production off CMB limits source of UHE protons (E > 5 1019eV) distances to less then ~50 – 100 Mpc Nuclei, g, & grains– don’t do any better Fe – diffuse infrared background g – radio background e+e- production grains– UV background No Counterparts: No Astronomy Yet !!! above 1019eV maybe at 1018eV Highest-Energy Cosmic Rays

The photopion production cutoff ~ 7 x1019 eV is not observed! No GZK Cutoff !!!

Consistent with Haverah Park & Fly’s Eye experiments Extragalactic UHECRs Protons, nuclei and gamma rays lose energy in intergalactic space

Proton energy vs. distance (J. Cronin) Energy loss on Cosmic Microwave Background The UHECR Challenge Energy: = 1020 eV Flux: = 1 particle/km2/century Spectrum: J ~ E-3, 1015eV < E < 1018eV, J ~ E-2 to E-1, E > 5 1019eV, NEW COMPONENT?? UHECRs vs. EHECRs or SCRs?

Cosmography: Arrival Directions ˜ Isotropic don’t see: Galaxy, Local Group, Local SuperCluster In future could see: Halo of Galaxy(???), AGNs? But above 1020eV only 7 (AGASA) - 20 events!

Composition: m content on the ground and depth of shower Max FE event: Proton or Fe – not g?? AGASA: trend is unclear – same as lower Energy Cluster of Events: (Takeda et al 99) Doublets & Triplets = 4 1019eV (2.5o) (1% chance) Indicates Long Lived Sources or Clumpiness or Focusing FACING THE CHALLENGE

NO Model Fits All the Data (without some “Miracle” B!)

Outer Space : Use Known Physics and Astrophysics Discard some piece of the Data ZEVATRONs Bottom-Up

Inner Space: Let Your imagination Free Top-Down why walk up if we can take the ski-lift? Bottom-Up ZEVATRONs = Astrophysical Accelerators reach ZeV’s Energy: = 1020 eV is the 1st challenge (If 1 TeV is hard imagine 109 TeV!!) nd Propagation: the 2 challenge Bigm (determines the spectrum and arrival direction) Acceleration = Macroscopic motions transferred to particles a la Fermi Hillas plot: require particles to be contained, ie, Gyroradius < size of Accelerator Not many objects left: Neutron Stars AGNs Radio Lobes Clusters Colliding Galaxies/Clusters Bursts Neutron Stars:

If to close to the polar cap - High Losses (Venkatesan, Miller, & A.O.’97) but Outside the light cylinder... Young Winds (Blasi, Epstein, A.O. ’00, A.O., Epstein, Blasi ’99) Neutron stars are born w/ large B & W slow down by B & Gmn radiation Iron nuclei accelerated from light cylinder by relativistic MHD winds

11 21 (G ˜10 ) reach Emax ˜ 10 eV Column density of SNR envelope needs to below enough for the Iron nuclei to escape while star still spins fast -1 This Zevatron is a ‘‘Cyclotron’’ B ˜ r , r > Rlc Particle contained in accelerating region

Tests: Spectrum FLAT!! N(E) ˜ E-1 Composition: Iron Location: Galactic plane for the highest energies AGNs:

Central Regions High energy g observed - 19-20 Emax˜10 eV but too many losses (Norman,Melrose, Achterberg ‘95) GZK plus Cosmography hurt.

Dead Quasars maybe but GZK cut! (Bolt & Ghosh ‘99)

Radio Lobes 21 Emax= 10 eV (Rachen & Bierman ‘93) 22 Emax= 10 eV (Bierman ‘00) But, in general they are Too far!! Except for M87,

Need very specific BGal & Bigm M87 Clusters Cluster Accretion Shocks 19-20 Emax˜10 eV (Kang, Ryu, & Bierman ‘95)

Galactic Winds 19 Emax˜10 eV (Jokopii & Morfill ‘85) Even if energy is close, they don’t get out (Blasi ‘99)

Gamma Ray Bursts Transient Relativistic Shocks Similar p & g fluxes (Waxman ‘95) Relativistic shocks: not enough G (Achterberg ‘99) flux too low (Stecker ‘99)

-10 0.5 needs Bigm = 10 G E20/d30 /l1 Half & Half Aproach:

New Particles from Astrophysical Zevatrons For Ex: Uhecrons - Heavy-quark composites (Chung, Farrar, & Kolb ‘98) FE shower development says: Not above 50 GeV (Albuquerque, Farrar, & Kolb ‘98)

Monopoles (Weiler & Kephart‘96) No also: (FE shower development) Unless… (Wick, Kephart, Weiler & Bierman‘00)

UHE scatter off n background: Z-pole (Weiler ‘82)

Needs Very High Energy (High Flux) Source

Tests: No Clustering!!! Gamma primaries Top-Down Physics Beyond the SM Energy >> 1020 eV is Easy! (Usually start at 1023 eV or higher!!) -1 Flux is the challenge!! (determined by typical separation scales – H0 ) & Composition!! Topological Defects generated in the early Universe through the Kibble Mechanism – as symmetries are broken. (Hill 83, Hill, Schramm, & Walker 87, Bhattacharjee, Hill, Schramm 92, Sigl, Bhattacharjee, Schramm 94)

Super Conducting Strings (Hill, Schramm &Walker ‘85) Cosmic Strings (Bhattacharjee & Rana ‘90) Monopolia (Hill 83, Bhattacharjee & Sigl 95) String Cusps (Brandenberger ‘87) Monop-String Network (Berezinsky Martin &Vilenkin97) Necklaces (Berezinsky & Vilenkin 97) Vortons (Masperi & Silva 98)

Super Heavy Relic particles Metastable (Kuzmin &Rubakov 97; Berezinsky, Kachelriess, &Vilenkin 97) – Halo Distribution - small percentage decays today - Cryptons, … Early Universe Relics produced after or at the end of , decay today producing X-particles that decay QCD fragmentation spectrum Cosmic Strings & Superconducting Strings are too far apart – Flux too low! Monopole-Anti-Monopole: G Þ H x U(1) Too Many – Inflate – Too Few – Fine Tune!!! Monopolonia Orbits decay‘99)

Monopoles w/ Strings Attached G Þ H x U(1) Þ H x ZN acceleration of monopoles create UHECRs – Flux too low! Cosmic Necklaces N=2 above. Distance between beads can be just right :– OK!

SuperHeavy Relics: live long via Symmetry Protection Plan (Chung, Kolb, & Riotto 98, Kuzmin & Tkachev 98) 12 long lived – weakly interacting = CDM Mx > 10 GeV (Berezinsky, Blasi, and Vilenkin 98) EGRET constrains g flux at 10 MeV and 100 GeV Þ Constrains UHE g’s and e’s via secondary lower energy g’s (CMB & Radio Background) )

Signatures: Composition: fragmentation lead to g >> proton Spectrum: QCD fragmentation NOT Power law like the Zevatrons! Halo Distribution!! (SHRs & Local TDs) The CHALLENGE is back in Experimental Arena

Bottom-Up Signatures: Protons/Nuclei Power Law Spectrum Counterparts (or B)

Top-Down Signatures: Photons Non-Power Law Spectrum No Counterparts/ Repeats Halo Distribution International Collaboration 2 Giant AirShower Arrays South – Argentina Funded North – Utah Not Funded Yet 1600 particle detectors spread over 3000 km2 + 4 Fluorescence Detectors/each Will Measure Direction, Energy, & Composition of ~60 events/year E > 1020eV ~6000 events/year E > 1019eV + Horizontal Showers = UHE Neutrinos! Auger Project

Combined Fluorescense & Ground Array detectors Auger Detectors Auger vs. AGASA Engineering Array from satellite Pampa Amarilla Site First Tank - Priscila The Size of Auger Auger Collaboration UHECRs Mystery +...

AGASA sees (2000): 8 events E >1020 eV 728 events E >1019 eV

Auger will see (3yr): ~100 events E >1020 eV ~10000 events E >1019 eV … + UHE Neutrinos!!!!

HORIZONTAL SHOWERS Can Probe:

Neutrino Cross Sections Above the Standard Model

Tau showers from the Earth or the Andes Fly’s Eye saw 0 !! But there are GZK n’s!! 19 -29 2 þ snN (10 eV) = 5 10 cm

SM Auger can reach ~ snN þ probe interactions beyond Standard Model 19 SM -30-31 2 snN (10 eV) = snN ~10 cm

Auger can also detect t decays! 17-18 nt (10 eV) produce t’s

Andes (50 km) or Ground (upward nt’s)

nm Ö nt Full mixing þ GZK nt ‘s !!! EUSO - OWL – Airwatch

Ni Fluorescence from ABOVE! = 30 x Auger 3000 events/year E > 1020eV !!!

UHE Neutrinos! The Pierre Auger Project

Engineering Array Starting this Spring!!

Full Project On ~ 2003 STAY TUNED!!!!