The Super-Kamiokande Collaboration
Super-Kamiokande and IceCube- two complementary approaches to
neutrino astronomy..thanks to many for providing slides (knowingly
or not )IceCube Counting House
Kamioka Mountain
Lutz KpkeJohannes Gutenberg University MainzCCAPP, Columbus,
Ohio, April, 4, 2011OutlineIntroduction, detector principles and
sensitivitiesNeutrino oscillation physicsHigh energy neutrino
astronomyCore collapse supernovae
Main objectives of Super-Kamiokande and IceCube:Determine
properties, interactions and QM of neutrinosTest extensions of our
standard field theory larger symmetry groups (e.g. Proton Decay)
additional symmetries (e.g. Super-Symmetry) symmetry violations
(CPT, Lorentz etc. )Discover origin of cosmic rays and nature of
cosmic catalcysms
1. Introduction and detectorsNobel Prize 2002A professor
denounced me as being no good at physics. That made me furious. So
I took the entrance exam for the physics department.
Moisei Alexandrovich MarkovMid 1950s: proposal for deep
underground and underwater neutrino observatoriesMasatoshi Koshiba
Grandfathers of astronomyMarkov warned the soviet leaders in 1947
about dangerous political-ideological moves that threaten to
separate soviet science from thre rest
This was a brave (almost suicidal) move, as he and other
scientists were charged of not sufficiently quoting Russian
scientists and uncritically receiving western physical theories and
propagandizing them in our countryStalin, however, chose the atomic
bomb over ideology which saved their lives
Later, Markov became active in promoting disarmament
3Fluxes of cosmic neutrinos
under-groundoptical:- deep water- deep ice air showers radio
acousticsKamiokande also uses neutrinos from accelerator beams
(e.g.
T2K)Super-Kamiokande199619971998199920002001200220032004200520062007200820092010
11146 PMTs(40% coverage)
5.0 MeV5182 PMTs(19% coverage)
7 MeV11129 PMTs(40% coverage)
5 MeVTotal energy threshold
Acrylic (front)+ FRP (back)
ElectronicsUpgradeSK-ISK-IISK-IIISK-IV~4.5 MeV < 4.0 MeV
achieved goal120 collaborators, 31 institutions, 6 countries Will
provide data for a long time (2025)!
supernovae, proton decay
The IceCube Observatory
1000 m1000 m1450 m80 sparsely instrumented strings 17 m vertical
sensor distance 125 m horizontal string distance
6 densely instrumented strings (DeepCore) 7-10 m sensor distance
60 m horizontal string distance
5160 sensors + autonomous DAQ in iceDecember 2010: IceCube fully
deployed !!!
250 collaborators, 36 institutions, 9 countries IceCube
accumulated exposure
for 100 TeVThe interesting time is now !Factor 300 since
2000data available 7Complementary approaches
Imaging detector: 40% PMT coverage
precision detector: Calibration uncertainties O(%) Sparse
sampling detector < 1% PMT coverage
discovery instrument: Systematic uncertainties O(10-20%)
~125 m~17 mBoth detect all neutrino species ( e ) ,but are
optimized for very different energy ranges and neutrino fluxes Size
comparison and energy coverage
IceCube: 1000 Mton
DeepCore: 15 MtonSuper-K: 0.05 Mton1 MeV10 MeV 100 MeV 1 GeV10
GeV 100 GeV 1 TeV 10 TeV 100 TeVIceCubeDeepCore
extensionSuper-Ksolar SN proton decay atmospheric neutrinos
(extra)galactic 9II. Neutrino Oscillations
10000 20000 30000 40000 km/GeVeprobability0.2 0.4 0.6 0.8
1.0frequency:mi2-mj2 E / LSchematically: e
mixing angles:12,23,13Neutrinos
propagating mass eigenstate weak interactions eigenstatesunknown
CP violationonly limit 13< 10o knownwould like improved
precision at the end one would like to understandwhy neutrinos mix
differently than quarks Present knowledge (Lisl, Neutel2011): 12 =
(33.6+1.2-1.0)o (~ 3%) 23 = (40.4+5.2-3.5)o (~ 11%) 13 < 13o
m22-m12 = (7.54+0.25-0.21) x 10-5 [eV2] (~ 3%) m32-m22 =
(2.36+0.12-0.10) x 10-3 [eV2] (~ 5%)
normal invertedMore specific questions that can be answered in
neutrino oscillation experimentsCan we see appearance of ? (
Opera)How large is 13?Is there CP-violation in the neutrino
sector?What is the neutrino hierarchy?
Low-energy solar n + e- n + e- candidatecolor: timeEe =
9.1MeVcosqsun = 0.95~ 6 hits / MeV (SK-I, III, IV)SK-III resolution
10 MeV electrons: vertex: 55 cm direction: 23o energy: 14%
Timing information: vertex position
Ring pattern: direction
Number of hit PMTs: energySK-IV up to Nov. 2010
13
Three-Flavor Analysis (including SK-I+II+III) 68, 95, 99.7% C.L.
13 = 9.1+2.9-4.7o ( < 14o at 95%C.L.), but consistent with 0
!Solar -results
arXiv:1010.0118KamLANDtan212
Solar globalKamLANDSolar+KamLANDPreliminary tan212sin213m212
[eV2]
Zenith angle distributions atmospheric sSuper-Kamiokande
I+II+III, 2806 days oscillation (fit)no oscillatione-like
m-likeClear deficit !No e deficit ! determine 23 m223 limit 13,
observe ?
99% C.L.90% C.L.68% C.L.best fitFull 3-flavor oscillation
resultsSK-I+II+IIINormal hierarchy Super-K preliminary
0.84000.4Inverted hierarchy 3003.5x10-31.5x10-311.5x10-3No
significant hierarchy differenceor constraint on CP at 90% CL
!0.4030003.5x10-3SK: best constraint on 23 Minos: sharper
constraint on m23
Minos 90%CL16
99% C.L.90% C.L.68% C.L.best fitFull 3-flavor oscillation
results (SK I-III)0.4No significant hierarchy difference or
constraint on CP at 90% CL !03000SK: best constraint on 23 Minos:
sharper constraint on m23
Super-K preliminary1.5x10-33.5x10-3Minos 90%CL similar, but less
constraint for inverse hierarchyNormal hierarchy 17
e or or hadronsEnergy threshold: 3.5 GeV
events at Super-KNegligible primary flux Any observed
oscillation induced ! but: complicated event topologyGOAL : test
the null hypothesis of no appearance
Fitted excess inconsistent with no appearance at 3.8s Exotic
Oscillations (IceCube)Quantum gravity effects: Lorentz invariance
violation and quantum decoherencestandard oscillations 1/Equantum
gravity oscillations E (or E2)
Muon neutrino survival
probabilityconventionaloscillationsDeepCoreVLI oscillations,c/c =
10-27 e.g. VLI: speed of light = f(neutrino flavor): parameters:
c/c, sin 2, Phase
excludedsin 2 Log c/c-27-25III. High energy astronomy
highest energy event255000 photo-electrons!if muon bundle: E ~
1016 eVWaxman-Bahcall limitIdea: constrain possible neutrino flux
from extragalactic cosmic ray intensity neutrinos must be created
in cosmic ray beam dumps
Extragalactic flux
IceCube sensitivityAssume p (and pp, pn) interaction in
surrounding materialpions and kaons neutrinos Assume optically thin
sourcesExtrapolate to lower energy assuming flux ~ 1/E2WB upper
limit () depends on many assumptions WB: expect flux 1/5? there are
also many specific models (AGN, GRB, galactic sources )IceCube sky
map (50% of detector)
hottest spot post-trial value 18%
no discovery yet ! Live time 375 days, 14121 upgoing events,
22779 downgoing eventsLimits for point sources with flux 1/E2
Factor1000in 15 years !
Complementarity in dark matter searches
direct detectionindirect detectionProduction at LHC
colliderDirect searches profit from coherent interaction on nucleon
( A2) telescopes profit from large detection volumespin-independent
cross sectionallowed modelsspin-dependent cross sectionSensitivity
direct searchesSensitivity IceCube (Super-K)e.g. Cohen, Phalen,
PiercePhys. Rev. D81, 116001 (2010)
Excluded by direct detection experiments for spin-dependent
interactionIceCube/Amandalimit (W+,W-)Dark matter sensitivity spin
dependent Super-K (2009)Prel. limit (W+,W-)
IceCube/DeepCoresensitivity (W+,W-)IceCube: sensitivity 100 x
direct search experiments (sun mostly hydrogen!)Non-excluded even
if SI- limits improved by 1000MSSM scanpreliminary
continuing to higher energies look for excess of , e etc on top
of atmospheric neutrinosSpectrum of atmospheric 100 TeV=1014 eV
study energies above O(50) TeV
Extraterrestric - diffuse fluxWaxman-Bahcall boundIceCube 40
strings: 5 excluded the Waxman-Bahcall bound has been crossed EGADS
Schedule2009-10: Excavation of new underground experimental hall,
construction of stainless steel test tank and PMT-supporting
structure (all completed, June 2010)
2010-11: Assembly of main water filtration system (completed),
tube prep, mounting of PMTs, installation of electronics and DAQ
computers
2011-13: Experimental program, long-term stability assessmentAt
the same time, material aging studies will be carried out in Japan,
and transparency and water filtration studies will continue in the
USThe goal is to be able to state conclusively whether ornot
gadolinium loading of Super-Kamiokande will besafe and effective.
Target date for decision = mid-201228
IV. Core collapse supernova detection Milky Way: 2 1 core
collapse supernovae per century
with 3 supernovae/century, probability of observation:
25 % within 10 years45% within 20 years
Goal: get most of physics out of this precious event Relic
neutrinos neighboring galaxies?Energy release E
R=1010 m star collapses via a Rcore=106 m core to a RNS =104 m
neutron star E EEkin 10-2 EEem 10-4 Eindividual neutrino energy ~ E
/Ndominant reaction: e+ p e+ + n
cross section: E2 (count events - SK) Cherenkov light: E3 (count
s - IceCube)8.8 M progenitor O-Me-Mg core (1s after bounce) rates
strongly dependent on energies
track length ~ 0.57 cm x Ee+ (MeV) N300-600nm ~ 180 x Ee+
(MeV)29
Interaction vertices in IceCubeview from aboveDark noise: ~ 540
Hz/DOM can be reduced somewhat
dominant reaction: e+ p e+ + n
cross section: E2 (events - SK) Cherenkov light: E3 (s -
IceCube)
Idea: track coherent increase of total rate due to neutrinos on
top of low dark noise
Effective volume: ~30 m3/MeV of e+Effective volume overlap small
O(1%)30Expected rate distribution (IceCube)
Lawrence Livermore model, 10 kpc distance (~ distance to
center)IceCube Monte Carlo with time dependent energy spectra
incorporatednormal neutrino hierarchyinverted neutrino
hierarchyTotani et al. Astrop. Phys. 496, 216
(1998)preliminarybackground levelclear differences in model shapes
for normal and inverted hierarchy!31
More exotic signals to hope for quark star formation black hole
formation no explosion!
normal invertedHierarchy Dasgupta et al., Phys. Rev. Lett. D 81,
103005 (2010)anti- peak!Sumiyoshi et al., ApJ 667, 382 (2007)black
holeformation>40 solar mass progenitor
no oscillationsnormal hierarchy inverted hierarchy32How does
IceCube compare?Due to noise background, the answer depends on the
signal/noise assumption which is a function of distance, model and
time within bursttake this plot with a big grain of salt !
example: comparison of initial 0.38 sLawrence Livermore
model!60% milky waycoverage equivalent mass background free
detector (Mton) 0.25 MtonSuper-K IceCube 1 Mton
0.1 Mton
0.01 Mtondistance [kpc] 0 10 20 30 40 50 60Super-K: 10% chance
to see SN in Andromeda33Super-K and IceCube make a good team
.IceCube: Mton scale detector for close supernovae study fine
details of neutrino light curve
Super-K: energy, direction + some type separation low background
handle for relic neutrinos
Aim for combined analyses!!discuss at workshop Talk M.
Smydirectional information 25o/NThe future (Super-Kamiokande)T2K
300 km base line experiment J-PARC Super-K; first interactions
2010!Goal: test 13 down to 5x10-3 dependent on CP-phase ; reach 13
~ 4o by mid 2011T2K 13 sensitivity1020 1021 1022Protons on
target4.0o1.5oJuly 2011 goal?
Gd loading test facilityLarge n capture Gd+nG* Gd+
8 MeV total E200 ton tank 250 PMTsAdd gadolinium to water for
efficient antineutrino tagging talk Michael Smy Goal: Determine by
mid-2012 if Gadolinium loading will be safe and effectiveOne
candidate for e appearance!
Not significant
29% probability forbackground fluctuationO0.5 GeV
0.3 backgroundevents expected Earth quake, but no Tsunami
damage; Super-Kamiokande is fineProblems: Power, some outer
structuresEarth quake damage at J-PARC
Dump south37 the future (IceCube)Find extra-terrestrial
neutrinos!
Soon results from DeepCore extension with (10) GeV energy
threshold:
bridge gap to Super-K to study atmospheric oscillations, Wimps,
galactic sources
Think about even denser in-fill with O(1) GeV threshold?
Dream about future ice lab for low energy physics and proton
decay?
DeepCore(IceCube veto)IceCubeSuper-K38SummarySK-IV is running
with the lowest energy threshold ever! 100% efficiency at Etotal~
4.5MeVFull 3-flavor atmospheric and solar oscillation results More
stringent proton decay limitsR&D for Gadolinium in Super-K is
underway (results 2012)Very efficient data taking for T2K beam
High sensitivity gradient for IceCubes analysesSensitivity has
crossed Waxman-Bahcall boundComplementarity to direct dark matter
searchesMton scale experiment for close supernovaeOne year of data
from low energy extension DeepCoreIdeas about future extensions
being gathered
39
40The Super-Kamiokande Collaboration1 Kamioka Observatory, ICRR,
Univ. of Tokyo, Japan2 RCCN, ICRR, Univ. of Tokyo, Japan3 IPMU,
Univ. of Tokyo, Japan4 Boston University, USA5 Brookhaven National
Laboratory, USA6 University of California, Irvine, USA7 California
State University, Dominguez Hills, USA8 Chonnam National
University, Korea9 Duke University, USA10 Gifu University, Japan11
University of Hawaii, USA12 Kanagawa, University, Japan13 KEK,
Japan14 Kobe University, Japan15 Kyoto University, Japan16 Miyagi
University of Education, Japan17 STE, Nagoya University, Japan18
SUNY, Stony Brook, USA19 Niigata University, Japan20 Okayama
University, Japan21 Osaka University, Japan22 Seoul National
University, Korea23 Shizuoka University, Japan24 Shizuoka
University of Welfare, Japan25 Sungkyunkwan University, Korea26
Tokai University, Japan27 University of Tokyo, Japan28 Tsinghua
University, China29 Warsaw University, Poland30 University of
Washington, USAFrom PRD81, 092004 (2010)~120 collaborators31
institutions, 6 countriesAutonomous University of Madrid, Spain
(Nov.2008~)
USA:University of Alaska, AnchorageUniversity of Alabama,
Tuscaloosa Bartol Research Institute, Delaware University of
California, BerkeleyLawrence Berkeley National Lab.Clark-Atlanta
UniversityGeorgia TechUniversity of California, IrvineLawrence
Berkeley National LaboratoryUniversity of MarylandOhio State
University Pennsylvania State UniversitySouthern University and
A&M College, Baton RougeUniversity of
Wisconsin-MadisonUniversity of Wisconsin-River
FallsSweden:Stockholm UniversitetUppsala UniversitetUK: Oxford
UniversityBelgium: Universit Libre de Bruxelles Vrije Universiteit
Brussel Universiteit Gent Universit de MonsGermany: RWTH
AachenUniversitt BochumUniversitt BonnDESY-ZeuthenUniversitt
DortmundHumboldt UniversittMPI Heidelberg Universitt
MainzUniversitt WuppertalJapan: Chiba UniversityNew Zealand:
University of Canterbury36 institutions, ~250 members
http://icecube.wisc.eduSwitzerland: EPFLIceCube
CollaborationBarbados:University of the West Indies41PAS CITER TOUS
LES PAYS MAUS JUSTE UW HALZENcamera at 2450 m depth
Ice and freeze-in properties in itself interesting .42General
theoretical lessons on sAt least two neutrinos have (very small)
massesMasses are probably small, because s are of Majorana type
(masses inverse proportional to large scale of lepton number
violation)Mass ~MR empirically close to 1014-1015 GeV ~ MGUTDecays
of right handed neutrinos produce baryogenesis via
leptogenesis0.025 m2 (normal hierarchy): m2/m3~0.2 (close to c ~
0.22 ?)very small 13 and maximal 23 (45o) theoretically hard
Operas nutau candidate
nu tau candidate opera
44Search for p e+ + p0 SK-I+II+III+IV
proton / B > 1.21 x1034 yr SK-I-IV combined (205.7
kton/year): no candidates!Signal MCDataPreliminary should reach 2 x
10-34 by 2017 if no candidates are found
Nucleon decay limits, status 2010 Proton is stable in the
standard model GUT. SUSY models allow p decay, but predict
different channels and lifetimes!46limited by number of protons
(SK: 7.5 x 1033) and neutrons (SK: 6.0 x 1033) background and time
!! Lifetime sensitivity 2010202020303x10342x1034pe+01x1034
Phys Lett B587:105-116 (2004)Comparison with an SO(10)
ModelSuper-K data are providing strong constraints to these models
But need sensitivity ~ 1036 years to rule out minimal SUSY ???
47
Expected significancedepends on detection technique as well as
model and neutrino properties > 25 in Galaxy
~ 3-10 in Magellanic cloudspreliminary48