Transcript Document

EHE Cosmic Rays (HE1.4, 1.5, 2.1)
Shigeru Yoshida
Department of Physics
Chiba University
29th ICRC Pune
29th ICRC Pune
No GZK ?
When I was a rapporteur 6 years ago (ICRC Salt Lake)
7 events above 1020 eV
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Anisotropy : UHECR Sky?
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New measurements
 HiRes
Two FD Eyes allows STEREO observation
• HiRes1
Most statistics above 10 EeV
Only 1 ring
• HiRes2
Lower Threshold Energy (~0.2 EeV)
2 rings
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New measurements
 Auger
SD (Ground Array) + 3(+1) FD Eyes
• SD
50% Completed
~1500 km2
• FD
3 Eyes completed
mostly for Energy Calibration
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Present Exposure @ 1019 eV
 HiRes1 (mono)
 HiRes (Stereo)
 Auger
~5000 km2 sr yr
~2500 km2 sr yr
1750 km2 sr yr ~ AGASA
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HiRes Aperture
HiRes-2 mono
 Stereo data: best
resolution, optimized for
E>31018eV Uses timedependent calibration of
detector and atmosphere
 HiRes-2 monocular: can
reach down to as low as
1017.2eV
 HiRes-1 monocular data
began ~3 years earlier:
largest statistics,
 Uses profile
constrained fit (PFC)
unreliable <1018.5eV
Wayne Springer (this conference)
HiRes stereo
HiRes-1 mono
HiRes
Apertures
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HiRes 1 (mono)
“GZK” Statistics
• Expect 42.8 events
• Observe 15 events
• ~5 s
Bergman (this conference)
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HiRes 1 (mono)
Integral Spectrum
Flux attenuation starts
At around 1019.75 eV
Consistent with the GZK hypothesis
Bergman (this conference)
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You need some caution
 HiRes1 is strongly BIASED measurement.
It’s MONOCULAR and only 1 ring! Viewing limited volume
of the atmospheric volume.
 Aperture continues increasing with energy
 Profile constrained fit to estimate energy
Stereo measur. should provide a confident data
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HiRes Stereo Flux
 Fit to power law.
 Single index
gives poor chi2
 Evidence for
changing index
Wayne Springer (this conference)
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HiRes Stereo (and others)
 Exhibits cutoff
structure
Expect 33.7 events
Observe 9 events
~4.8s
 Some details
DIFFERENT from
mono!
The Mono spectrum may
contain unknown syst.
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Some Remarks
 HiRes Stereo
Cut “sort of” narrow Opening angle events
Require careful estimation of detect. Eff.
Scanning simple parameters continues
 AGASA conflicts
Energy scale? Old MC?
 Auger
Hybrid measurement
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Auger Hybrid
Paul Sommers (this conference)
Log (E) = -0.79 + 1.06
Log(S38)
E = 0.16 S381.06
(E in EeV, S38 in VEM)
Uncertainty in this rule
increases from 15% at 3
EeV to 40% at 100 EeV
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Auger SD spectrum
 Energy scale uncer.
still large
~40 % in 100 EeV
improvement will come
soon
Paul Sommers (this conference)
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S(1000): The energy indicator
(Ghia, this conference)
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S(1000): The energy indicator
 Less mass composition sensitive
Not just muons but emg component make sizable contributions
(Alan Watson, private comminication)
 S(1000)Fe-P
~10 % difference (Paul Sommers, private com)
 s s(1000)
~15% @ 10 VEM (Ghia, this conference)
BUT ALL these rely on EAS MC!!
S.Yoshida
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A scary scenario
When more statistics
Intrinsic fluctuation
Of EAS development!!
(Sako, this conference)
LHCf
interaction point
96mm
140m
The beam pipes of LHC are separated by 96mm at 140m
from the interaction point.
Charged particles are swept out by magnets.
LHCf measures the distribution of the Feynman x parameter
(practically energy) of neutral particles emitted in the very
forward region using position sensitive calorimeters placed
in this 96mm gap.
LHCf Prototype test
Main detector
Silicon tracker
for position
calibration
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Event cluster > 40 EeV
No significant excess: AGASA’s triplet Pch ~0.28
(Westerhoff, this conference)
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AGASA triplet story
HiRes stereo event
6060
60°
180
°
180
°
170
°
170
°
One event added – BUT below 40 EeV!!
(Westerhoff, this conference)
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HiRes: BL Lac correlation?
“BL” BL Lacs with m<18, all HiRes events (no energy cut):
F = 2×10-4
All confirmed BL Lacs (“BL+HP”) with m<18, HiRes E>10 EeV:
F = 10-5
Confirmed TeV blazars, all HiRes events (no energy cut):
F = 10-3
These are not independent results: the samples overlap.
Analysis has been a posteriori, so F values are not true chance
probabilities.
(Finley, this conference)
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HiRes2 Mono:
Galactic anti-center?
(Thomson, this conference)
(Letessier-Selvon, this conference)
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Auger: Galactic Center
Coverage
Significance (1.5º)
3.0
2.0
1.0
300
270
240
0.0
-1.0
-2.0
Significance (3.7º)
Significance (13.3º)
-3.0
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Mass Compositon (Xmax)
Filled circles, HiRes; Triangles,
HiRes/MIA, Open circles, Fly’s Eye
(shifted).
HiRes+Fly’sEye(shifted)
LightHeavyLight?
(Sokolsky, this conference)
1EeV
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Particle Physics Outputs
HiRes : s inp  Air  456 17 ( stat )  39( sys )  11( sys ) mb
(Mathews, this conference)
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So What we have seen?
 GZK strikes back!
Needs cautions on energy scale, but the spectrum is
consistent with the cutoff
 No anisotropy…. Except some possible indication..
Deficit in anti-galactic center, BL-Lac correlation
Then… what we can do to pin down UHECR origin ?
ADDING MORE (GOOD) DATA!
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Multi Wavelength
Particle spices observation
 GZK photons/Neutrinos
lead to information on EHE cosmic ray source distribution,
radio background, and extragalactic B.
 Photon-induced EAS search
LPM + Geomagnetric Preshower effects  Xmax anomaly
•HiRes (O’Neill, this conference)
•Auger (Risse, this conference) Fg(Eg>10EeV) < 26 %
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EHE Neutrino Observatory
 Deeply penetrating inclined EAS search
Auger (Nellon, this conference) HiRes ….
 IceCube (In-ice Cherenkov light detector)
(Chirkin, this conference)
 Rice (In-ice Cherenkov Radio detector)
 ANITA (In-Flight Cherenkov Radio detector)
(Duvernois, this conference)
 Acoustic Extension (In-ice Acoustic detector)
(Nahanhauer, this conference)
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IceCube
IceTop
1km3!
Deep Ice Array
(Chirkin, this conference)
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IceCube
Conventional Technique extends up to EHE!
1EeV t
300 PeV cascade
IceCube
Yoshida et al PRD 69 103004 (2004)
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“Hybrid” tech to extend ++1km3
“conventional” detector provides “test” beam!
 Use IceCube holes
3 distant holes
down to 400 m
 7 stations per hole
sensor, transmitter,
auxiliary det. per station
 Deployment
January 2006
Results
Summer 2006
Rolf Nahanhauer (this conference)
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Future Outlook
 Auger: 7 x AGASA by 30th ICRC
 HiRes: <2 years STEREO data to be analyzed.
~70% more statistics
“independent” dataset for testing the “BL Lac”
 New observatory in the Northern sky
Telescope Array
Telescope Array
576 plastic scintillation
Surface Detectors (SD)
5 communication
towers
3m2 1.2cm t
Atmospheric
fluorescence
telescope
3 stations FD
Middle Drum
SD
two layers
1.2km spacing
Black Rock Mesa
Long Ridge
20km
Sensitivity of SD : ~9 x AGASA
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Test Observations @ Millard county, Utah
(Ogio, this conference)
3-13 July, 2005 @ Black Rock Mesa site
Single telescope with 256ch PMTs camera
Typical waveform with fluorescence light
(RUN65,TRIG165, CH89)
Total observation time: 31.5 hours
s5 ADC count =
2.5 p.e./100 ns
1st level trigger threshold: 6 - 6.5 sigma
Trigger rate: 0.6 - 1.5 Hz
An observed shower-like track (11 July, 2005)
ch#
Recorded waveforms
degree
Analysis result
SDP
dc
cc
ba
preliminary
aa
99
89
78
logE(eV) = 18.05
68
57
46
Xmax = 674.9 g/cm2
q = 46.2o
35
Relative time
degree
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Future Outlook
 Auger: 7 x AGASA by 30th ICRC
 HiRes: <2 years STEREO data to be analyzed.
~70% more statistics
“independent” dataset for testing the “BL Lac”
 New observatory in the Northern sky
Telescope Array
• EHE gamma ray/Neutrino search
EAS detector, IceCube, Rice, ANITA etc.
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Thank you!
Nos vemos en Mejico!!
S.Yoshida