Carlos de los Heros Division of High Energy Physics Uppsala University EPS2005
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Transcript of Carlos de los Heros Division of High Energy Physics Uppsala University EPS2005
Carlos de los HerosCarlos de los HerosDivision of High Energy Division of High Energy PhysicsPhysicsUppsala UniversityUppsala University
EPS2005EPS2005Lisbon, July 21-27, 2005Lisbon, July 21-27, 2005
GETTING THERE:GETTING THERE:FROM AMANDA TO ICECUBEFROM AMANDA TO ICECUBE
USA: Bartol Research Institute, Delaware Univ. of Alabama Pennsylvania State University UC Berkeley UC Irvine Clark-Atlanta University Univ. of Maryland IAS, Princeton University of Wisconsin-Madison University of Wisconsin-River Falls LBNL, Berkeley University of Kansas Southern University and A&M
College, Baton Rouge
Sweden: Uppsala Universitet Stockholm Universitet Kalmar Universitet
In March 2005, AMANDA merged into the IceCube collaboration
UK: Imperial College, London Oxford University
Netherlands: Utrecht University
Belgium: Université Libre de Bruxelles Vrije Universiteit Brussel Universiteit Gent Université de Mons-Hainaut
Germany: Universität Mainz DESY-Zeuthen Universität Dortmund Universität Wuppertal Universität Berlin
Japan: Chiba university
New Zealand: University of Canterbury
THE ICECUBE COLLABORATIONTHE ICECUBE COLLABORATION
• Cosmic rays @ >>TeV exist
acceleration sites must sit somewhere
Candidate sources:• SNe remnants, Quasars• Active Galactic Nuclei• Gamma Ray Bursts• Exotics (decays of topological defects...)
proton accelerators
Neutrinos : not absorbed, not deflected:
difficult to detect
Protons : deflected in magnetic fields, GZK -rays : propagate straight, however:
– reprocessed in sources– absorbed in IR (100 TeV) and 3K (10 PeV)
?
explained explained by SN?by SN?
unexplainedunexplained
Guaranteed sources:
• atmospheric neutrinos (from & K mesons decay)
• galactic plane: – CR interacting with ISM, concentrated on the disk
• CMB (diffuse):– UHE p + n + (p 0)
NEUTRINO ASTRONOMYNEUTRINO ASTRONOMY
PMT noise: ~1 kHz
AMANDA-B10(inner core of AMANDA-II)
10 strings302 OMs
Data years: 1997-99
Optical Module
“Up-going”(from Northern sky)
“Down-going”(from Southern sky)
AMANDA-II
19 strings677 OMs
Data years: 2000 –
THE AMANDA DETECTORTHE AMANDA DETECTOR
AMANDA-B4(first 4-string prototype)
4 strings80 OMs
Data years: 1996
1996 1997 2000
What’s up?
Amundsen-Scott South Pole station
South Pole
Stationfacilities
AMANDA
road to work
1500 m
2000 m
[not to scale]
THE SITETHE SITE
NEUTRINO DETECTION IN POLAR ICENEUTRINO DETECTION IN POLAR ICE
O(km) long muon tracks
~15 m
7.0)TeV/(7.0 E
South Pole ice: (most?) transparent
natural condensed material
Longer absorption length → larger effective volume
Event reconstruction by Cherenkov light timing
O(10m) Cascades, e Neutral Current
IN THIS TALK:IN THIS TALK:
•Results from:
atmospheric neutrinos
searches for an extra-terrestrial flux: galactic center
diffuse (anytime, anywhere)point source (anytime, somewhere)transient (known ‘flary’ objects & GRBs) (sometime, somewhere)
search for WIMPs: Excess from the center of the Sun/Earth
SN search in the Milky Way
Agreed collaboration strategy: Analyses are done ‘blind’. Cuts optimized on a % of data or on a time-scrambled data set.
AMANDA: sensitive in very different energy regimes
Energy range production site(s)Energy range production site(s)
MeV Supernovae
GeV-TeV
Atmosphere
Dark matter from Sun/Earth
Galactic center
TeV-EeV
Quasars
SN remnant
AGN
GRB
galactic
extragalactic
EHadron E-2.7 0.02
cosmic ray muonsAtmospheric muons: - AMANDA test beam: I vs depth, CR composition - Background for other searches
TEST BEAMS: TEST BEAMS: ATMOSPHERIC ATMOSPHERIC MUONSMUONS
SPASE (scintillator array @ 3000m) e density @ surface shower core resolution: 0(m) shower direction resolution: < 1.5o
AMANDA ‘s @ >1500m (>300 GeV @ surface) use SPASE core position for combined fit use expected lateral photoelectron/event distribution as estimate of N
Combined SPASE-AMANDA ‘detector’:
Probes hadronic () and EM (e) component of the primary shower
(E) ~ 0.07 in log(Eprim)
Results compatible with composition change around the knee
Sources of systematic uncertainties:(~30% in ln(A), not shown in the plot)
-shower generation models -muon propagation
►Neural Network energy
reconstruction of up-going μ`s
►Regularized unfolding
→ energy spectrum
Set limit on cosmic neutrino flux:
How much E-2 cosmic ν - signal
allowed within uncertainty of highest energy bins?
Limit on diffuse E-2 νμ flux (100 -300 TeV):
First spectrum > 1 TeV (up to 300 TeV)- matches lower energy Frejus data
E2μ(E) < 2.6·10–7 GeV cm-2 s-1 sr-1
vertical
horizontal
TEST BEAMS: TEST BEAMS: ATMOSPHERIC NEUTRINOSATMOSPHERIC NEUTRINOS
Frejus
Amanda
Atmospheric neutrinos: - Guaranteed test beam - Background for other searches
’’s s FROM THE GALACTIC PLANEFROM THE GALACTIC PLANE
•Expected from CR+galactic interstellar
medium
• ’s follow the primary energy spectrum, E-
2.7
•Location of AMANDA reach only outer
region of the galactic plane: 33o<<213o
•data sample 2000-03: 3329 evts
•Three signal ansatz:
•Line source
•Gaussian source
•Diffuse sourceNO EXCESS OBSERVED:
Optimal Optimal on-source on-source
regionregion
on-source on-source eventsevents
Expected bckg.Expected bckg.
+-2.0o 128 129.4
6.4x10-5 (line)
(GeV-1 cm-2 s-1 rad-1)
6.6x10-4 (diffuse)
(GeV-1 cm-2 s-1 sr-1)
+-4.4o 271 283.34.8x10-4 (gauss) (*)
(GeV-1 cm-2 s-1 sr-1)
(*)
Several strategies in the search for point sources:
•Diffuse flux of neutrinos with no time-space correlations. Focus on E-2 spectrum
•calculate upper limit on high energy tail of atmospheric νμ
• optimize selection with attention to background(s) rejection
•multi-flavor (muon tracks + cascades)
•Spacial correlation with steady objects•Search for clusters of events (w. or w.o. catalogue)•Stacking of known point source candidates (paper in preparation)
• Space and/or time correlation with transient phenomena •known active flary periods of TeV gamma sources•time window-rolling search of signal excess over background
SEARCH FOR POINT SOURCESSEARCH FOR POINT SOURCES
•UHE: E > P eV:
•Earth opaque
•Search in the upper
hemisphere and close to the
horizon
•Bright events: many hit OMs with several hits/OM Energy -related variables best handle of analysis
DIFFUSE SEARCHDIFFUSE SEARCH
•HE: TeV < E < PeV:
•Use directionality + energy-related
variables to reject atm background
•Search confined to up-going tracks
•Use high-quality tracks
Limit from data sample 1997. 131 d lifetime:
Assuming a E-2 flux (1 PeV < E < 3 EeV) and
e:: = 1:1:1
E2 all(E) < 9.9 x 10-7 GeV cm-2 s-
1 sr-1
Sensitivity from data sample 2000. 174 d lifetime:
Assuming a E-2 flux (0.2 PeV < E < 2 EeV)
and e:: = 1:1:1
E2 all(E) < 4.2 x 10-7 GeV cm-2 s-
1 sr-1
Limit from data sample 1997. 131 d lifetime:
Assuming a E-2 flux (1 PeV < E < 3 EeV) and
e:: = 1:1:1
E2 (E) < 8.4 x 10-7 GeV cm-2 s-1 sr-1
Sensitivity from data sample 2000-03. 807d lifetime:
Assuming a E-2 flux (13 TeV < E < 3.2 PeV) and
e:: = 1:1:1
E2 all(E) < 9.5 x 10-8 GeV cm-2 s-1
sr-1
Analyses optimized for , : reduced sensitivity to e and All-flavour
•Cascades: TeV < E < PeV
•4search
•Background: brehmm.
from down-going muons
Limit from data sample 1997. 131 d lifetime:
Assuming a E-2 flux (50 TeV < E < 3 PeV) and
e:: = 1:1:1
E2 all(E) < 9.8 x 10-6 GeV cm-2 s-1
sr-1
Sensitivity from data sample 2000. 174 d lifetime:
Assuming a E-2 flux (50 TeV < E < 5 PeV) and
e:: = 1:1:1
E2 all(E) < 8.6 x 10-7 GeV cm-2 s-1
sr-1
signal:
background:
AMANDA
1: B10, 97, ↑μ2: A-II, 2000, unfold.3: A-II, 2000, cascade4: B10, 97, UHE6: A-II, 2000, UHE sensit.7: A-II, 2000-03 ↑μ sensit.
Baikal
5: 98-03, casc.
1:1:1 flavor flux ratio
all-flavor limits
DIFFUSE SEARCHES: SUMMARYDIFFUSE SEARCHES: SUMMARY
Limits for other flux predictions: Cuts optimized for each case.
Expected limit from a given model compared with observed limit.
Some AGN models excluded at 90% CL :
Szabo-Protehoe 92
Stecker, Salamon. Space Sc. Rev. 75, 1996
Protehoe. ASP Conf series, 121, 1997
67
SEARCH FOR CLUSTERS OF EVENTS IN THE NORTHERN SKYSEARCH FOR CLUSTERS OF EVENTS IN THE NORTHERN SKY
•Search for excesses of events compared to the background from:
• the full Northern Sky• a set of selected candidate sources
•Cuts optimized in each declination band
•Require good pointing resolution (good quality events)
•Background estimated from exp. data
with randomized α (i.e. time)
•Sensitivity flat up to horizon•Significant improvement w.r.t. first analysis with AMANDA-B10
av
era
ge
flu
x u
pp
er
lim
it [
cm
-2s
-1]
sin
AMANDA-B10
AMANDA-II
Average upper limit = sensitivity (δ>0°)
(integrated above 10 GeV, E-2 signal)
tim
e
declination 0o (horizontal)
90o (vertical)
Declination averaged Declination averaged sensitivity sensitivity
for a Efor a E-2-2 spectrum and E spectrum and E > 10 > 10
GeVGeV
lim 0.6·10-8 cm-2s-1
Maximum significance: 3.4
Assess statistical significance using random sky maps:
Probability of a background
Fluctuation: 92%
Data from 2000-2003 (807 days)
3369 from northern hemisphere
3438 expected from atmosphere
Event selection optimized for both dN/dE ~ E-2 and E-3 spectra
SEARCH FOR CLUSTERS OF EVENTS IN THE NORTHERN SKYSEARCH FOR CLUSTERS OF EVENTS IN THE NORTHERN SKY
Source Nr. of events
(4 years)
Expectedbackgr.
(4 years)
Flux Upper Limit 90%(E>10 GeV)
[10-8cm-2s-1]
Markarian 421 6 5.58 0.68
1ES1959+650 5 3.71 0.38
SS433 2 4.50 0.21
Cygnus X-3 6 5.04 0.77
Cygnus X-1 4 5.21 0.40
Crab Nebula 10 5.36 1.25
Selected objects and full scan of the northern
sky:
No statistically significant effect observed
… out of 33 Sources
Systematic uncertainties under investigation
Sensitivity ~2for 200 days of “high-state” and spectral results from HEGRACrab Nebula: The chance probability of such an excess (or higher) given the number of trials is 64%
Prelim
inary
SEARCH FOR CLUSTERS OF EVENTS FROM KNOWN OBJECTSSEARCH FOR CLUSTERS OF EVENTS FROM KNOWN OBJECTS
On-Source
Off-Source
Source
Nr. of events
(4 years)
ExpectedBG
(4 years)
Period duration
Nr. of doublets
Probability for highest
multiplicity
Markarian 421 6 5.58 40 days 0 Close to 1
1ES 1959+650 5 3.71 40 days 1 0.34
3EG J1227+4302 6 4.37 40 days 1 0.43
QSO 0235+164 6 5.04 40 days 1 0.52
Cygnus X-3 6 5.04 20 days 0 Close to 1
GRS 1915+105 6 4.76 20 days 1 0.32
GRO J0422+32 5 5.12 20 days 0 Close to 1
Search for excesses in time-sliding windows:galactic objects: 20 daysextra-galactic objects: 40 days
Preliminary
… out of 12 Sources → no statistically significant effect observed
eventstime
sliding window
Enhance the detection chance by using the time information:
Search for neutrino flares without a-priori hypothesis on their time of occurrence
POINT SOURCE SEARCH: TIME WINDOW EXCESSPOINT SOURCE SEARCH: TIME WINDOW EXCESS
• Catalogues: BATSE+IPN3
• Several search techniques: • coincidence with T90• precursor (110s before T90)• cascades (all flavour, 4)
-coincident with T90
-rolling time window
(no catalogue)
• Bckg. Stability required within ±1
hour from burst• Further searches: rolling search
(without temporal/spacial constrains) Eν
2Φν < 6.7x 10-6 GeV cm-2 s-1 sr-1
SEARCH FOR SEARCH FOR ’s’s CORRELATED WITH GRBs CORRELATED WITH GRBs
Low background analysis due to both
space and time coincidence!
year#
GRBfrom
preliminary 90%CL upper limit
assuming WB spectrum
(EB at 100 TeV and = 300)
'97 - '00 312BATSE
triggered bursts
E2d/dE = 4 · 10-8 GeV cm-2s-1 sr-1
'00 - '03 139 BATSE & IPN bursts
E2d/dE = 3 · 10-8 GeV cm-2 s-1 sr-1
'01 - '03 50 IPN bursts(Assuming the Razzaque model)
E2d/dE = 5 · 10-8 GeV cm-2 s-1 sr-1
'01 (425) Rolling window
E2d/dE = 2.7 · 10-6 GeV cm-2s-1sr-1
'00 76BATSE
triggered bursts
E2d/dE = 9.5 · 10-7 GeV cm-2s-1sr-1
Sun analysis possible due to improvedreconstruction capability for horizontal tracks in AMANDA-II compared with B10.
• m 20%, b 5%
non-baryonic matter MSSM: candidate
• accumulating over cosmological time in the Sun/Earth. Pair-wise annihilation at its center:
and consider (MC=DarkSusy)• (soft channel)• (hard channel)
for various masses (50-5000 GeV)
HZ,W,,ll,qq -xx
bbxx -WWxx
SEARCH FOR SEARCH FOR DM CANDIDATES IN THE SUN/EARTHDM CANDIDATES IN THE SUN/EARTH
Combined 1997-99 data sets: Searches from the center of the Earth2001 data set: Search from the
Sun
Cygnus-X1
Cassiopeia. ASun
90 000 light years
SMC
LMC
Crab Nebula•Burst of low-energy (MeV) neutrinos from core collapse supernovae
increase indetector noise ratedue to e+e- e- + X
•Low energy O(ev)e- tracks: no pointing
•Monitor noise of subset of stable OMs
•Special DAQ: count rates in 10 s
•92% coverage of theMilky Way
•AMANDA part of SNEWS alert network
SEARCH SEARCH FOR SNe EXPLOSIONS IN THE GALAXYFOR SNe EXPLOSIONS IN THE GALAXY
Approximate AMANDA horizon
Deep ice array: IceCube Digital readout technology (D-OMs) 80 strings / 60 DOM’s each 17 m DOM spacing 125 m between strings hexagonal pattern over 1 km2x1 km
1200 m
IceTop
IceCube
Surface array: IceTop• 80 stations air shower array.
(one per IceCube string)• 2 tanks (2 DOMs each) per station• 125 m grid, 1 km2 at 690 g/cm2
• Ethreshold ~ 300 TeV for > 4 stations in coincidence
The IceCube observatory: IceCube+IceTopThe IceCube observatory: IceCube+IceTop
Amundsen-Scott South Pole station
South Pole
Stationfacilities
AMANDA
road to work
1500 m
2000 m
[not to scale]
IceCube
IceCube
THE SITE
Eµ=6 PeV
IceCube: an All-Flavor Neutrino Telescope
IceCube will be able to identify tracks from for E > 100 GeV cascades from e for E > 10 TeV for E > 1 PeV
Background mainly downgoing cosmic ray (bundles)(+ uncorrelated coincident 's)
- exp. rate at trigger level ~1.7 kHz- atm. rate at trigger level ~300/day
e e “cascade”
E = 375 TeV
~300
m @
E
= 1
PeV
"cascade"
1 year sensitivity a point E2·d/dE flux
IceTop Stations with DOMs – January 2004
Digitized muon signals from DOMs
Am
plit
ude
(AT
WD
cou
nts)
vs
tim
e (n
s)
power cable
signal, freeze control,
temperature controlcables
27.1, 10:08: Reached maximum depth of 2517 m, reversed direction, started to ream up
28.1, 7:00: drill head and return water pump are out of the hole, preparations for string installation start
7:52: Handover of hole for deployment
9:15: Started installation of the first DOM (DOM 60)
12:06: 10th DOM installed
22:36: 60th DOM installed Typical time for DOM installation:12 min
22:48: Start drop
29.1, 1:31: String secured at depth of 2450.80 m
20:40: First communication to DOM
IceCube First String: January 2005
An IceCube-IceTop event
OutlookOutlook
•A wealth of results from AMANDA-B10 and AMANDA-II on several physics
topics
•Results from combined analysis using several years ’00-’03 (more on the way)
•No extraterrestial neutrinos observed yet
•Sensitivity reaching the level of current predictions of production in AGN.
Some models already excluded @ 90%CL
•Digitized readout since 2003: waveform resolution
•First IceTop station deployed on Jan. 2004
•First IceCube string deployed on Jan. 2005
•First IceCube-IceTop and IceCube-AMANDA events seen
•IceCube/IceTop will significantly improve astrophysics and cosmic rays
measurements in energy range and resolution