Transcript Recent Experimental Results on Ultra High Energy Cosmic Rays James W. Cronin TeV Particle Astrophysics II Madison August 29, 2006

Recent Experimental Results on
Ultra High Energy Cosmic Rays
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James W. Cronin
TeV Particle Astrophysics II
Madison
August 29, 2006
1020 eV proton
16 joules energy
Kinetic energy of Yanick
Noah’s second serve
But momentum of a snail
Macroscopic energy in
a microscopic particle
No known astrophysical
sources “seem” able to
produce such enormous
energies
1/ km2/ century
3000 km2 -> 30
events / year
Simon Swordy
University of Chicago
proton + cmb ->  + nucleon
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Two techniques:
• detect shower particles
on the ground
• detect air fluorescence
produced by shower
particles
High Resolution Fly’s Eye
12.5km
QuickTime™ and a
GIF decompressor
are needed to see this picture.
HiRes I - 22 mirrors, 256 PMT/mirror, sample and hold, 360o azimuth, 17oelevation, - (‘98-).
HiRes II - 42 mirrors, 256 PMT/mirror, FADC electronics - 3600 azimuth, 300 elevation (‘99 -)
AGASA
Akeno Giant Air Shower
Array
111 Electron Det.
27 Muon Det. 100 km2
0
4km
AGASA
Summary
M. Teshima
International Conference on High Energy Physics
Moscow 2006
Super GZK particles exist
– Preliminary study with recent CORSIKA simulation
• If we evaluate energies with the recent CORSIKA simulation
– Energy scale shift down by ~10% at 1019eV and by ~15% at
1020eV
– 11 events above 1020eV / 1.3~2.6 expected
 5~6 events / 1.0~1.9 expected
– The flux difference between AGASA and HiRes becomes less
significant
Argentina
Australia
Bolivia*
Brasil
Czech Republic
France
Germany
Italy
Poland
Mexico
Slovenia
Spain
United Kingdom
USA
Vietnam*
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The Pierre Auger Observatory
38° South, Argentina, Mendoza,
Malargue 1.4 km altitude, 850
g/cm 2
Malargue 
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August 28, 2006
975 tanks operating
1100 installed
1600 operating by
end of 2007
The Surface
Array
Detector Station
Communications
antenna
Electronics
enclosure
GPS antenna
Solar panels
Battery box
3 – nine inch
photomultiplier
tubes
Plastic tank with
12 tons of water

S1000 is
Energy parameter
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Signal processing can extract em/muon ratio
Event 762577
32 stations
Energy ≈8x1019 eV
by inclined shower
algorithm
PRELIMINARY !!
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Old Shower: pure muons
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79 de gre e s
~?? Ee V
Wine&Cheese, Fermilab, July 15, 2005
Aaron S. Chou for the Pierre Auger Collaboration
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Large event
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52 tanks !
aerial view of Los Leones
fluorescence station
tanks aligned seen from Los
Leones (test your eyes)
tanks aligned seen from Los
Leones (zoomed)
A “perfect” hybrid event: few are as beautiful as this one !
Miguel Mostafa
New Mexico/Utah
SD energy ~ 1019.8
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Normalized to 1.0 at
sec theta = 1.27 or
theta = 38 deg
Attenuation curve by constant intensity technique
Measured from data
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not simulated
Pierre Auger Observatory
Some science topics
Spectrum
Inclined Events
Fluorescence Yield
Neutrino Limits
Elongation Rate
Anisotropy (Diego Harari)
Photon Limit (Markus Risse)
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James W. Cronin
TeV Particle Astrophysics II
Madison
August 29, 2006
ICRC 2005
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Comparison with HiRes1,
AGASA
John Matthews
Rencontres du
Vietnam
vietnam.in2p3.fr/2006
32,000 Inclined showers ≥ 600
Energy reconstruction
Log(E/EeV) = 0.73 ± 0.03 + (1.04 ± 0.06) log(N19)
Hybrid data: FD versus SD reconstruction
Inclined showers > 60 deg
Event 767138
 = 87.6
 = -134.9
E = 49.2
R= 19 km
/dof =1.7
NTanks = 37
Preliminary !
Expect 1-2
GZK neutrinos
per year
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Theoretical uncertainty
± factor 3
Preliminary !
Theoretical uncertainty
± factor 3
Exercise for neutrino limits
Do not trust!
“Not even wrong”
W.Pauli
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Anisotropy
report by Diego Harari
Presented at
6th Rencontres du Vietnam, 2006
vietnam.in2p3.fr
80,000 evts
Energy > 17.9 eV
Photon limits
reported by Markus Risse
At Rencontres du Vietnam 2006
vietnam.in2p3.fr
Northern Site
Lamar

Northern Site
Southeastern Colorado
Energy ≥ 1019 eV
1.6 km square grid (mile)
Tanks with 1 pmt only
 Lamar
A single FD
300
x
3600
Propose 10,000 km2