Antiproton and Electron Measurements and Dark Matter Indirect Searches
Piergiorgio Picozza INFN and University of Rome Tor Vergata
8th International Workshop On Identification Of Dark Matter
26-30 Jul 2010, Montpellier, France AstrophysicsAstrophysics andand CosmologyCosmology compellingcompelling IssuesIssues
ApparentApparent absenceabsence ofof cosmologicalcosmological AntimatterAntimatter
NatureNature ofof thethe DarkDark MatterMatter thatthat pervadespervades thethe UniverseUniverse SearchSearch forfor thethe existenceexistence ofof AntimatterAntimatter inin thethe UniverseUniverse
PAMELA AMS AMS in Space
S ea e rc rs h ve fo ni r t U he he e f t xi o st in en g ce ori o e f Accelerators th an r ti fo Un h iv arc er e se S
The Big Bang origin of the Universe requires matter and antimatter to be equally abundant at the very hot beginning THE UNIVERSE ENERGY BUDGET Robert L. Golden Balloon data : Positron fraction before 1990
mχ=20GeV Tilka 89
dinamic halo
leaky box ANTIMATTER Annihilation of Exotic Particles Collision of High Energy Cosmic Rays with the Interstellar Gas
Cosmic Rays Leaking Out of Antimatter Galaxies e - Evaporation of + p Primordial Black e p e+ Holes e+ p p e+
He e - Antimatter Lumps In the Milky Way e+
e+
Pulsar’s magnetospheres AntimatterAntimatter DirectDirect researchresearch
ObservationObservation ofof cosmiccosmic radiationradiation holdhold outout thethe possibilitypossibility ofof directlydirectly observingobserving aa particleparticle ofof antimatterantimatter whichwhich hashas escapedescaped asas aa cosmiccosmic rayray fromfrom aa distantdistant antigalaxyantigalaxy,, traversedtraversed intergalacticintergalactic spacespace filledfilled byby turbulentturbulent magneticmagnetic fieldfield,, enteredentered thethe MilkyMilky WayWay againstagainst thethe galacticgalactic windwind andand foundfound itsits wayway toto thethe EarthEarth..
Streitmatter, R. E., 24th ICRC , Rome, Italy, 1995 Nuovo Cimento, 19, 835 (1996)
HighHigh energyenergy particleparticle oror antinucleiantinuclei Dark Matter Candidates
•Kaluza-Klein DM in UED •Kaluza-Klein DM in RS •Axion •Axino •Gravitino •Photino GM(r) v(r) = •SM Neutrino r •Sterile Neutrino •Sneutrino •Light DM •Little Higgs DM •Wimpzillas •Q-balls •Mirror Matter •Champs (charged DM) •D-matter •Cryptons •Self-interacting •Superweakly interacting •Braneworld DM •Heavy neutrino •NEUTRALINO L. Roszkowski •Messenger States in GMSB •Branons •Chaplygin Gas •Split SUSY •PrimordialILIAS 6thBlack AnnualHoles Meeting , February 16th - 19st, 2009 Dresden Aldo Morselli, INFN Roma Tor Vergata 9
Another possible scenario: KK Dark Matter Lightest Kaluza-Klein Particle (LKP): B(1) Bosonic Dark Matter: fermionic final states no longer helicity suppressed. e+e- final states directly produced.
As in the neutralino case there are 1-loop processes that produces monoenergetic γγin the final state. DMDM annihilationsannihilations DM particles are stable. They can annihilate in pairs.
Primary annihilation channels Decay Final states
σa= <σv> PositronsPositrons detectiondetection Where do positrons come from? Mostly locally within 1 Kpc, due to the energy losses by Synchrotron Radiation and Inverse Compton scattering
Typical lifetime
Antiprotons within 10 Kpc DecayDecay ChannelsChannels e- AntimatterAntimatter SearchSearch
Wizard Collaboration
9 MASS – 1,2 (89,91) 9 BESS (93, 95, 97, 98, 2000) 9 TrampSI (93) 9 Heat (94, 95, 2000)
9 CAPRICE (94, 97, 98) 9 IMAX (96) 9 BESS LDF (2004, 2007)
9 AMS-01 (1998) Charge-dependent solar modulation CosmicCosmic RayRay AntimatterAntimatter Asaoka Y. Et al. 2002 Pre-PAMELA-Fermi status
Antiprotons Positrons Moskalenko & Strong 1998 Positron excess? Solar polarity reversal 1999/2000
¯
+
CR + ISM → p-bar + … kinematic threshold: 5.6 GeV for the reaction CR + ISM →π± + x →μ± + x → e± + pp → pppp x CR + ISM →π0 + x →γγ→e± WhatWhat diddid wewe needneed??
MeasurementsMeasurements atat higherhigher energiesenergies
BetterBetter knowledgeknowledge ofof backgroundbackground
HighHigh statisticsstatistics
ContinuousContinuous monitoringmonitoring ofof solarsolar modulationmodulation
LongLong DurationDuration FlightsFlights DarkDark MatterMatter SpaceSpace MissionsMissions PAMELA ATIC BESS 15-06-2006 12-2007 2002 - 2007
AMS-02 2010 GLAST/Fermi 11-6-2008 PAMELAPAMELA Payload for Antimatter Matter Exploration and Light Nuclei Astrophysics
PAMELAPAMELA
LaunchLaunch 15/06/15/06/0606
16 Gigabytes trasmitted daily to Ground NTsOMZ Moscow OrbitOrbit CharacteristicsCharacteristics
350 km SAA
70ο
610 km • Low-earth elliptical orbit • 350 – 610 km • Quasi-polar (70o inclination) • SAA crossed AntiprotonsAntiprotons AntiprotonAntiproton fluxflux
•PAMELA AntiprotonAntiproton toto protonproton ratioratio
•PAMELA SAA
Trapped pbar
•PAMELA
GCR
• PAMELA PositronsPositrons PositronPositron toto allall electronelectron ratioratio Nature 458, 697, 2009
PAMELA
Secondary production Moskalenko & Strong 98 PositronPositron FractionFraction
Pre lim in ary Positron Fraction
Pulsar Component Yüksel et al. 08
KKDM (mass 300 GeV) Hooper & Profumo 07
Pulsar Component Atoyan et al. 95
Pulsar Component Zhang & Cheng 01
Secondary production Moskalenko & Strong 98 A Challenging Puzzle for Dark Matter Interpretation DataData fittingfitting Which DM spectra can fit the data? DM with and dominant annihilation channel (possible candidate: Wino) positrons antiprotons
s! e o! Y N DataData fittingfitting
DM with and dominant annihilation channel antiprotons positrons
! s s! e e Y Y
s! e Y
ElectronsElectrons ry ary ina n imi lm reli Pre P Spectrum Spectrum ) ) - - PAMELA Electron (e PAMELA Electron (e ry a in m li re P Spectrum Spectrum ) ) - - PAMELA Electron (e PAMELA Electron (e ry a in m li re P Spectrum Spectrum ) ) - - 0.02 PAMELA Electron (e PAMELA Electron (e AllAll electronselectrons
ee++ ++ ee-- Courtesy Luca Baldini
All three ATIC flights are consistent
Preliminary Preliminary
ATIC 1 ATIC 1+21+2+4 ATIC 2 ATIC 4
“Source on/source off” significance of bump for ATIC1+2 is about 3.8 sigma J Chang et al. Nature 456, 362 (2008)
ATIC-4 with 10 BGO layers has improved e , p separation. (~4x lower background) “Bump” is seen in all three flights.
Significance for ATIC1+2+4 is 5.1 sigma Example:Example: DMDM I. Cholis et al. arXiv:0811.3641v1
I. Cholis et al. arXiv:0811.3641v1 See Neal Weiner’s talk FermiFermi ((ee++++ ee--)) ElectronsElectrons measuredmeasured withwith H.E.S.SH.E.S.S.. FermiFermi ((ee++++ ee--)) andand PAMELAPAMELA ratioratio BergstromBergstrom etet al.al. astroastro--phph 0905.0333v10905.0333v1 FermiFermi ((ee++++ ee--)) astro-ph 0912.3887 FermiFermi ((ee++++ ee--)) astro-ph 0912.3887
γ0=-2.7 PAMELAPAMELA allall electronselectrons Preliminary GammaGamma ConstraintsConstraints
γ from DM annihilation
± γ from Inverse Compton on e in halo -upscatter of CMB, infrared and starlight photons on energetic e±
(Constraints on cosmological dark matter annihilation from the Fermi-LAT isotropic diffuse gamma-ray measurement) astro-ph. 1002.4415v1 (Constraints on Dark Matter Annihilation in Clusters of Galaxies with the Fermi Large Area Telescope) astro-ph.1002.2239v1
± radio-waves from synchrotron radiation of e AstrophysicalAstrophysical ExplanationExplanation PulsarsPulsars S.S. ProfumoProfumo AstroAstro --ph ph 08120812 - Mechanism: the spinning B of the pulsar--44574457 strips e that accelerated at the polar cap or at the outer gap emit γ that make production of e± that are trapped in the cloud, further accelerated and later released at τ ~ 105 years.
5 Young (T ~10 years) and nearby (< 1kpc) If not: too much diffusion, low energy, too low flux.
Geminga: 157 parsecs from Earth and 370,000 years old B0656+14: 290 parsecs from Earth and 110,000 years old Many others after Fermi/GLAST
Diffuse mature pulsars Example:Example: pulsarspulsars
H. Yüksak et al., arXiv:0810.2784v2 Contributions of e- & e+ from Geminga assuming different distance, diffuse mature &nearby young pulsars age and energetic of the pulsar Hooper, Blasi, and Serpico arXiv:0810.1527 Pulsars: Most significant contribution to high-energy CRE: Nearby (d < 1 kpc) and Mature (104 < T/yr < 106) Pulsars
D. Grasso et al.
Example of fit to both Fermi and Pamela data with known (ATNF catalogue) nearby, mature pulsars and with a single, nominal choice for the e+/e- injection parameters AnisotropyAnisotropy
Fermi is performing a detailed study of dipole anisotropy and it is setting an upper limit. HowHow reliablereliable isis thethe backgroundbackground calculation?calculation?
Secondary production Moskalenko & Strong 98 CosmicCosmic RaysRays PropagationPropagation inin thethe GalaxyGalaxy Antiproton to proton ratio ProtonProton andand HeliumHelium fluxesfluxes ProtonProton toto HeliumHelium ratioratio
ATICATIC CREAMCREAM
astro-ph/0808.1718 δ = 0.33 top 0.6 med. 0.7 bot. TRACER 2006 Boron – Carbon Flux Ratio
Preliminary Analysis - 70% Aperture - Conservative cuts HEAO-3 CRN TRACER 2006 Energy bin (10-300 GeV/amu) from analysis of DEDX detector only. -1 10 - Boron 8,000 events - Carbon55,000 events Boron / Carbon Flux Ratio
Increased statistics over CRN
Expect several energy bins Preliminary after energy deconvolution -2 analysis 10 2 3 Analysis of events with 1 10 10 10 Kinetic Energy (GeV/amu) transition radiation signal underway (ie > 400 GeV/amu) B/CB/C
Preliminary PAMELAPAMELA preliminarypreliminary resultsresults
Li/C Be/C PositronPositron FractionFraction Solar Modulation of galactic cosmic rays
• Study of charge sign dependent effects Pamela AMS-01 Asaoka Y. et al. 2002, Phys. Rev. Lett. 88, 051101), Caprice / Mass /TS93 Bieber, J.W., et al. Physi-cal BESS Review Letters, 84, 674, 1999. J. Clem et al. 30th ICRC 2007 U.W. Langner, M.S. Potgieter, Advances in Space Research 34 (2004) Solar modulation Interstellar spectrum
(statistical errors only) Increasing GCR flux solar activity Decreasing July 2006 August 2007 February 2008
PAMELA Ground neutron monitor
sun-spot number
Charge dependent solar modulation +
¯ ¯
Pamela + 2006 (Preliminary!)
A > 0 A < 0
Positive particles BESS-Polar II Launch - December 22, 2007 BESS Detector
–Rigidity measurement JET/IDC – SC Solenoid (L=1m, B=1T) Rigidity – Min. material (4.7g/cm2)
– Uniform field TOF – Large acceptance β, dE/dx –Central tracker – (Drift chamber – δ ~200μm – Z, m measurement – R,β --> m = ZeR√1/β2-1 – dE/dx --> Z BESS Polar II Observations/Expectations • Event rate ~2.5 kHz; Total events ~4.7 x 109 • Total data volume 13.5 TB (3.07 kB/event) • Expected antiprotons ~10,000 10-20 times previous Solar minimum dataset
Antiproton Antideuteron Antihelium (Search for PBH) (Search for PBH) (Search for Antimatter) AMSAMS--0202 onon ISSISS InIn OrbitOrbit 20102010
TRD
Aarhus Kurchatov Inst. ESA Inst. of Theor. & Experimental Physics NIKHEF Helsinki Moscow State Univercity NLR, Amsterdam Turku Annecy Achen I & III Grenoble Montpellier Karlsruhe Munich Ciemat-Madrid Korea MIT Bucharest IHEP Ya l e IEE, IHEP Johns Hopkins LIP-Lisbon Bologna Florida Maryland Jiao Tong University Taiwan Milano Southeast University A&M Perugia Mexico ETH-Zurich Pisa CSIST Geneva Univ. Roma NCU Siena Academia Sinic NSPO Vacuum Tracker
Case MAGNET He Vessel
RICH TheThe CompletedCompleted AMSAMS DetectorDetector onon ISSISS Transition Radiation Detector (TRD) Time of Flight Detector (TOF)
Magnet Silicon Tracker
Electromagnetic Ring Image Cerenkov Calorimeter (ECAL) Counter (RICH)
Size: 3m x 3m x 3m Weight: 7 tons AMSAMS--0202 newnew configurationconfiguration AMSAMS CapabilityCapability SpaceSpace PartPart 20062006
Gamma Rays DirectDirect searchsearch forfor antimatter:antimatter: AMSAMS onon ISSISS
He Collect 2 billion nuclei with energies up to 2 trillion eV Li B C N O Ne Mg F Be Na Al Si P S Cl ArKCa Sc Ti V CrMn Fe Co y06K301
Atomic Number
Sensitivity of AMS: If no antimatter is found => there is no antimatter to the edge of the observable universe (~ 1000 Mpc). UniqueUnique positrons FeatureFeature antiprotons ofof AMSAMS
Combining searches in different channels could give (much) higher sensitiviy to SUSY DM signals
anti deuterons gamma rays TheThe NextNext FutureFuture PerspectivesPerspectives PerspectivesPerspectives ThanksThanks!!
http://http:// pamela.roma2.infn.itpamela.roma2.infn.it