antimatter and dark matter searches in space: the pamela space mission antimatter and dark matter...

Antimatter and Dark Matter Searches in Space: Antimatter and Dark Matter Searches in Space:

the PAMELA Space Missionthe PAMELA Space Mission

Piergiorgio Picozza INFN and University of Rome Tor Vergata

XIII Workshop on “Neutrino Telescopes”

VeniceMarch 10-13, 2009

PAMELAPAMELAPPayload for ayload for AAntimatter ntimatter MMatter atter EExploration xploration

and and LLight Nucleiight Nuclei AAstrophysicsstrophysics

PAMELA CollaborationPAMELA Collaboration

Moscow St. Petersburg

Russia:

Sweden:KTH, Stockholm

Germany:Siegen

Italy:Bari Florence Frascati TriesteNaples Rome CNR, Florence

PAMELA InstrumentPAMELA Instrument

GF ~21.5 cmGF ~21.5 cm2srsr Mass: 470 kg Mass: 470 kg

Size: 130x70x70 cmSize: 130x70x70 cm3

Design PerformanceDesign PerformanceEnergy range

Antiprotons 80 MeV - 150 GeV

Positrons 50 MeV – 300 GeV

Electrons up to 500 GeV

Protons up to 700 GeV

Electrons+positrons up to 2 TeV (from calorimeter)

Light Nuclei (He/Be/C) up to 200 GeV/n AntiNuclei search sensitivity of 3x10-8 in

He/He

Simultaneous measurement of many cosmic-ray species New energy range Unprecedented statistics

Resurs-DK1 satelliteResurs-DK1 satellite

Mass: 6.7 tonnesHeight: 7.4 mSolar array area: 36 m2

Main task: multi-spectral remote sensing of earth’s surface Built by TsSKB Progress in Samara, Russia

Lifetime >3 years (assisted) Data transmitted to ground via high-speed radio downlink

PAMELA mounted inside a pressurized container

PAMELAPAMELA

LaunchLaunch15/06/0615/06/06

16 Gigabytes trasmitted 16 Gigabytes trasmitted daily to Grounddaily to Ground

NTsOMZ MoscowNTsOMZ Moscow

OrbitOrbit Characteristics Characteristics

km

km

SAA

• Low-earth elliptical orbit

• 350 – 610 km

• Quasi-polar (70o inclination)

• SAA crossed

Download @orbit 3754 – 15/02/2007 07:35:00 MWT

S1 S2 S3

Inner radiation belt

(SSA)

orbit 3752 orbit 3753orbit 3751

NP SP

EQ EQ

Outer radiation belt

95 min

PAMELA OrbitPAMELA Orbit

The Physics of PAMELAThe Physics of PAMELA

Study of solar physics and solar modulation

Study of terrestrial magnetosphere

Study of high energy electron spectrum (local sources?)

Search for dark matter annihilation

Search for antihelium (primordial antimatter)

Search for new Matter in the Universe (Strangelets?)

Study of cosmic-ray propagation

(GLAST-FERMIAMS-02)

Signal (supersymmetry)…

… and background

Another possible scenario: Another possible scenario: KK Dark MatterKK 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-loopprocesses that produces monoenergeticγ γ in the final state.

PAMELA StatusPAMELA Status

• Today 1003 days in flight Today 1003 days in flight • data taking ~73% live-timedata taking ~73% live-time

• ~13 TBytes of raw data downlinked~13 TBytes of raw data downlinked

• >10>1099 triggers recorded and under triggers recorded and under analysisanalysis

AntiprotonsAntiprotons

Flight data: 84 GeV/c interacting antiproton

PAMELA antiproton PAMELA antiproton discriminationdiscrimination

Proton Spillover

PositronsPositrons

Bending in spectrometer: sign of charge

Ionisation energy loss (dE/dx): magnitude of charge

Interaction pattern in calorimeter: electron-like or proton-like, electron energy

Time-of-flight: trigger, albedo rejection, mass determination (up to 1 GeV)

PositronProton

Proton / positron discrimination Proton / positron discrimination

p (non-int)

ee--

ee++

p (non-int)

Fraction of energy released along the calorimeter track (left, hit, right)

p (int)

p (int)

Rigidity: 20-30 GV

Positron selection with Positron selection with calorimetercalorimeter

LEFT HIT RIGHT

strips

plan

es

0.6 RM

Positron selection with calorimeterPositron selection with calorimeter

ee--

Fraction of charge released along the calorimeter track (left, hit, right)

ppee++

+ •Energy-momentum match•Starting point of shower

Rigidity: 20-30 GV

Positron selection with Positron selection with calorimetercalorimeter

pp

ee--

ee++

pp

Flight data:rigidity: 20-30 GV

Fraction of charge released along the calorimeter track (left, hit, right)

Test beam dataMomentum: 50GeV/c

ee--ee--

ee++

•Energy-momentum match•Starting point of shower

(~R

M)

+-

Selections on total detected energy, starting point of shower

e- e+

(p)- p

Flight data: 51 GeV/cpositron

Positron selection with calorimeterPositron selection with calorimeter

ee--

Fraction of charge released along the calorimeter track (left, hit, right)

pp

ee++

+ • Energy-momentum match• Starting point of shower • Longitudinal profile

Rigidity: 20-30 GV

Positron selectionPositron selection

ee--

pp

ee--

ee++

pp

Neutrons detected by ND

Rigidity: 20-30 GVFraction of charge released along the calorimeter track (left, hit, right)

ee++

•Energy-momentum match•Starting point of shower

The “pre-sampler” The “pre-sampler” methodmethod

2 W planes: ≈1.5 X0

20 W planes: ≈15 X0

CALORIMETER: 22 W planes: 16.3 X0

The “pre-sampler” The “pre-sampler” methodmethod

POSITRON SELECTION

PROTON SELECTION

2 W planes: ≈1.5 X0

20 W planes: ≈15 X0

20 W planes: ≈15 X0

2 W planes: ≈1.5 X0

ee++ background estimation background estimation from datafrom data

+ • Energy-momentum match• Starting point of shower

e-

‘presampler’ p

Rigidity: 20-28 GV

e+

p

ee++ background estimation background estimation from datafrom data

+ • Energy-momentum match• Starting point of shower

e-

‘presampler’ p

Rigidity: 28-42 GV

e+

p

ee++ background estimation background estimation from datafrom data

+ • Energy-momentum match• Starting point of shower

e-

‘presampler’ p

Rigidity: 6.1-7.4 GV

e+

p

RESULTSRESULTS

Antiproton to proton ratioAntiproton to proton ratio PRL 102, 051101 (2009)PRL 102, 051101 (2009)

Seconday Production Models

Antiproton to proton ratioAntiproton to proton ratioPRL 102, 051101 (2009)PRL 102, 051101 (2009)

Antiproton FluxAntiproton FluxPrelim

inary

statistical errors onlyenergy in the spectrometer

Mirko Boezio, SLAC Seminar, 2009/01/12

Antiproton FluxAntiproton Flux

Preliminary

statistical errors onlyenergy in the spectrometer

Secondary production:F. Donato et al., 536 (2001) 172

Secondary production: V. S. Ptuskin et al, ApJ 642 (2006) 902

Prelim

inar

y

Positrons to all electrons ratioPositrons to all electrons ratio

Secondary production Moskalenko & Strong 98

Positron to Electron RatioPositron to Electron Ratioastro-ph 0810.4995astro-ph 0810.4995

InterpretationInterpretation

• 0808.3725 DM

• 0808.3867 DM• 0809.2409 DM• 0810.2784

Pulsar• 0810.4846 DM /

pulsar• 0810.5292 DM• 0810.5344 DM• 0810.5167 DM• 0810.5304 DM• 0810.5397 DM• 0810.5557 DM• 0810.4147 DM• 0811.0250 DM• 0811.0477 DM

During first week after PAMELA During first week after PAMELA results posted on arXivresults posted on arXiv

)

Secondary production Moskalenko & Strong 98

Pulsar ComponentAtoyan et al. 95

Pulsar ComponentZhang & Cheng 01

Pulsar ComponentYüksel et al. 08

KKDM (mass 300 GeV)Hooper & Profumo 07

PAMELA Positron FractionPAMELA Positron Fraction

Example: eExample: e++ & p DM & p DM

P. Grajek et al., arXiv: 0812.4555v1

See Gordon Kane’s talk

Astrophysical Explanation: Pulsars Astrophysical Explanation: Pulsars

S. Profumo Astro-ph 0812-4457S. Profumo Astro-ph 0812-4457

Positrons production and acceleration mechanismPositrons production and acceleration mechanism

Young Pulsars (T ~ 10Young Pulsars (T ~ 105 5 years) and nearby (< 1kpc) years) and nearby (< 1kpc) Too young: contribution does not escape from the nebula Too young: contribution does not escape from the nebula

cloud of the pulsar.cloud of the pulsar. Too old: much diffusion, low energy, too low flux.Too old: much diffusion, low energy, too low flux.

Geminga: 157 parsecs from Earth and 370,000 years oldGeminga: 157 parsecs from Earth and 370,000 years old B0656+14: 290 parsecs from Earth and 110,000 years old.B0656+14: 290 parsecs from Earth and 110,000 years old.

Diffuse mature pulsars?Diffuse mature pulsars?

Mirko Boezio, LHC & DM Workshop, 2009/01/06

Example: pulsarsExample: pulsars

H. Yüksak et al., arXiv:0810.2784v2Contributions of e- & e+ from Geminga assuming different distance, age and energetic of the pulsar Hooper, Blasi, and Serpico

arXiv:0810.1527

Standard Positron FractionStandard Positron FractionTheoretical UncertaintiesTheoretical Uncertainties

T. Delahaye et al., arXiv: 0809.5268v3

γ = 3.54 γ = 3.34

Explanation with supernovae Explanation with supernovae remnantsremnants Shaviz and al. astro-ph.HE Shaviz and al. astro-ph.HE

0902.03760902.0376

Only secondaries?Only secondaries?P. Serpico hep-ph 0810.4846P. Serpico hep-ph 0810.4846

Anomalous primary electron source spectrumAnomalous primary electron source spectrum Spectral feature in the proton flux responsible for Spectral feature in the proton flux responsible for

secondariessecondaries Role of Helium nuclei in secondary productionRole of Helium nuclei in secondary production Difference between local and ISM spectrum of Difference between local and ISM spectrum of

protonsprotons Anomalous energy-dependent behaviour of the Anomalous energy-dependent behaviour of the

diffusion coefficientdiffusion coefficient Rising cross section at high energiesRising cross section at high energies High energy beaviour of the eHigh energy beaviour of the e++/e/e--

PAMELA Proton SpectrumPAMELA Proton Spectrum

Galactic H and He spectraGalactic H and He spectraPrelim

inar

y !!!

Secondary nucleiSecondary nuclei

• B nuclei of secondary origin: CNO + ISM B + …

• Local secondary/primary ratio sensitive to average amount of traversed matter (lesc) from the source to the solar system

Local secondary abundance: study of galactic CR propagation

(B/C used for tuning of propagation models)

SPescP

S σλNN

LBM

Preliminary

Antiproton to proton ratioAntiproton to proton ratioPRL 102, 051101 (2009)PRL 102, 051101 (2009)

Positron FractionPositron Fraction

Solar Modulation of galactic cosmic rays

BESS

Caprice / Mass /TS93AMS-01

Pamela• Study of charge sign dependent effects

Asaoka Y. et al. 2002, Phys. Rev. Lett. 88, 051101),

Bieber, J.W., et al. Physi-cal 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 modulationInterstellar spectrum

July 2006August 2007 February 2008

Decre

asin

g

sola

r activ

ity

Incre

asin

g

GC

R fl

ux

sun-spot number

Ground neutron monitor PAMELA

(statistical errors only)

A > 0

Positive particles

A < 0

¯

+

¯

+

Pamela

2006

(Preliminary!)

Charge dependent solar modulation

Thanks!Thanks!

PAMELA Physics WorkshopPAMELA Physics WorkshopMay 11-12, 2009May 11-12, 2009

ROMAROMA

http:// pamela.roma2.infn.ithttp:// pamela.roma2.infn.it /workshop09/workshop09

A > 0 Positive particles A < 0

p, e+

p, e--

Secondary production Bergström et al. ApJ 526 (1999) 215

Secondary production (upper and lower limits)Simon et al. ApJ 499 (1998) 250.

from χχ annihilation

P

Proton fluxes at TOAProton fluxes at TOAAnnual Variation of P spectrum

Kinetic Energy (GeV)

Comparison of p/p ratio with model

Time variation of p/p ratio at solar maximum

Observed data by BESS

Charge dependent model

prediction(Bieber et al.)

Charge dependent solar modulation model well follows

the suddenly increase of p/p ratio observed by BESS

at the solar polarity reversal between 1999 and 2000

Solar Physics with PAMELASolar Physics with PAMELA

December 2006 Solar particle December 2006 Solar particle eventsevents

Dec 13th largest CME since 2003, anomalous at sol min

December 13th 2006 eventDecember 13th 2006 event

Preliminary!

Preliminary!

December 13th 2006 He December 13th 2006 He differential spectrumdifferential spectrum

December 14th 2006 event

Preliminary!

Solar Quiet spectrum

Low energy tail of Dec 13th event

Below galactic spectrum: Start of Forbush decrease

Magnetic Field

Neutron Monitor

X-ray

P,e-

Decrease of primary spectrum

Arrival of magnetic cloud from CME of Dec 13th

Shock 1774km/s (gopalswamy, 2007)

Decrease of Neutron Monitor Flux

Magnetic Field

Neutron Monitor

X-ray

P,e-

Arrival of event of Dec 14th

End of event of Dec 14th

Radiation BeltsRadiation Belts

South Atlantic AnomalySouth Atlantic Anomaly

Secondary production from CR Secondary production from CR interaction with atmosphereinteraction with atmosphere

SAA

SAA morphology

Lati

tud

eA

ltit

ude Altitude

Longitude

Neutron rate(background)

South-Atlantic Anomaly (SAA)South-Atlantic Anomaly (SAA)

•Grigorov, Sov. Phys. Dokl. 22, 305 1977•NINA ApJ Supp.132 365, 2001•AMS Phys. Lett. B 472 2000.215,

Phys. Lett. B 484 2000.10–22•Lipari, Astrop. Ph. 14, 171, 2000•Huang et al, Pys Rev. D 68, 053008 2003•Sanuki et al, Phys Rev D75 043005 2007•Honda et al, Phys Rev D75 043006 2007

Atmospheric neutrino contributionAstronaut dose on board International Space StationIndirect measurement of cross section in the atmosphere nell’atmosfera Agile e Glast background estimation

--- M. Honda, 2008

Proton flux at various cutoffs

Proton spectrum in SAA, polar and equatorial regionsProton spectrum in SAA, polar and equatorial regions

Other ObjectivesOther Objectives

High Energy electronsHigh Energy electrons The study of primary electrons is especially The study of primary electrons is especially

important because they give information on the important because they give information on the nearest sources of cosmic rays nearest sources of cosmic rays

Electrons with energy above 100 MeV rapidly Electrons with energy above 100 MeV rapidly loss their energy due to synchrotron radiation loss their energy due to synchrotron radiation and inverse Compton processes and inverse Compton processes

The discovery of primary electrons with energy The discovery of primary electrons with energy above 10above 1012 12 eV will evidence the existence of eV will evidence the existence of cosmic ray sources in the nearby interstellar cosmic ray sources in the nearby interstellar space (rspace (r300 pc) 300 pc)

CALO SELF TRIGGER EVENT: 167*103 MIP RELEASED279 MIP in S4 26 Neutrons in ND

An example is the search for “strangelets”.

There are six types of Quarks found in accelerators.All matter on Earth is made out of only two types of quarks. “Strangelets” are new types of matter composed of three types of quarks which should exist in the cosmos.

i. A stable, single “super nucleon” with three types of quarks

ii. “Neutron” stars may be one big strangelet

Carbon Nucleus Strangelet

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uudduuuudddd

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dd dd dddd dd

uuuu

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ssss

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uuuudd

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dddd uu

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dddd uu dddd uu dddd uudddd uu

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p n

AMS courtesy

Search for New Matter in the Universe:Search for New Matter in the Universe:

Positron selection with calorimeter

Test Beam Data