PAMELA Space MissionPAMELA Space Mission

Antimatter and Dark Matter ResearchAntimatter and Dark Matter Research

Piergiorgio Picozza INFN & University of Rome “ Tor Vergata” , Italy

TeV Particle AstrophysicsTeV Particle Astrophysics

23-28 September, 2008Beijing, China  

Robert L. Golden

AMSPAMELA AMS PAMELA AMS in Spacein Space

AcceleratorsAccelerators

The Big Bang origin of the Universe requires matter and antimatter

to be equally abundant at the very hot beginning

Search for the existence of anti Universe Search for th

e origin of th

e Universe

Search for the existence of Antimatter in Search for the existence of Antimatter in the Universethe Universe

Antimatter Direct Antimatter Direct researchresearch

AntimatterAntimatter which has escaped as a cosmic ray which has escaped as a cosmic ray from a distant antigalaxyfrom a distant antigalaxy

Sreitmatter, R. E., Nuovo Cimento, 19, 835 (1996)Sreitmatter, R. E., Nuovo Cimento, 19, 835 (1996)

AntimatterAntimatter from globular clusters of antistars in from globular clusters of antistars in our Galaxy as antistellar wind or anti-supernovae explosionour Galaxy as antistellar wind or anti-supernovae explosion

K. M. Belotsky et al., Phys. Atom. Nucl. 63, 233 K. M. Belotsky et al., Phys. Atom. Nucl. 63, 233 (2000), astro-ph/9807027(2000), astro-ph/9807027

4% 23% 73%

(GLAST AMS-02)

Signal (supersymmetry)…

… and background

Antimatter and Dark Matter Antimatter and Dark Matter ResearchResearch

-- BESS (93, 95, 97, 98, BESS (93, 95, 97, 98,

2000)2000)

- Heat (94, 95, 2000)- Heat (94, 95, 2000)

- IMAX (96) IMAX (96)

- BESS LDF (2004, 2007)BESS LDF (2004, 2007)

- AMS-01 (1998)AMS-01 (1998)

Wizard Collaboration- - MASS – 1,2 (89,91)MASS – 1,2 (89,91)

--TrampSI (93)TrampSI (93)

-CAPRICE (94, 97, 98)CAPRICE (94, 97, 98)

AntimatterAntimatter

“We must regard it rather an accident that the Earth and presumably the whole Solar System contains a preponderance of negative electrons and positive protons. It is quite possible that for some of the stars it is the other way about” P. Dirac, Nobel lecture (1933)

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 (Primary production m(c) = 964 GeV)

Ullio : astro-ph/9904086

P

CR antimatterAntiprotons Positrons

CR + ISM ± + x ± + x e± + x CR + ISM 0 + x e±

___ Moskalenko & Strong 1998 Positron excess?

Charge-dependent solar modulation

Solar polarity reversal 1999/2000

Asaoka Y. Et al. 2002

¯

+

CR + ISM p-bar + …kinematic treshold: 5.6 GeV for the reaction

pppppp

Present status

What do we need?What do we need? Measurements at higher energiesMeasurements at higher energies

Better knowledge of backgroundBetter knowledge of background

High statisticHigh statistic

Continuous monitoring of solar modulationContinuous monitoring of solar modulation

Long Duration FlightsLong Duration Flights

PAMELAPAMELAPPayload for ayload for AAntimatter ntimatter MMatter atter EExploration xploration

and and LLight Nucleiight Nuclei AAstrophysicsstrophysics

Pamela as a Space Observatory at 1AUPamela as a Space Observatory at 1AU

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

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 cm2sr sr Mass: 470 kg Mass: 470 kg Size: 130x70x70 cmSize: 130x70x70 cm3

Energy range

Antiproton flux 80 MeV - 190 GeV Positron flux 50 MeV – 270 GeVElectron/positron flux up to 2 TeV (from calorimeter)

Electron flux up to 400 GeVProton flux up to 700 GeVLight nuclei (up to Z=6) up to 200 GeV/n He/Be/C:Antinuclei search Sensitivity of O(10

-8) in He-bar/He

Design performanceDesign performance

• Unprecedented statistics and new energy range for cosmic ray physics

• Simultaneous measurements of many species

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

Flight data: 0.632 GeV/cantiproton annihilation

Flight data: 0.763 GeV/cantiproton annihilation

PAMELA StatusPAMELA Status

• ~630 days of data taking (~73% live-~630 days of data taking (~73% live-time) time)

• ~10 TByte of raw data downlinked~10 TByte of raw data downlinked

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

AntiprotonsAntiprotons

Flight data: 84 GeV/c interacting antiproton

PAMELA Protons SpilloverPAMELA Protons Spillover

Antiproton-Proton RatioAntiproton-Proton Ratio

PAMELAPreliminary

Antiproton to proton Antiproton to proton ratioratio

Preliminary

Antiproton to proton Antiproton to proton ratioratio

Antiproton to proton Antiproton to proton ratioratio

Preliminary

PositronsPositrons

Flight data: 92 GeV/cpositron

Mirko Boezio, INFN Trieste - San Diego IEEE2006Mirko Boezio, INFN Trieste - San Diego IEEE2006

Flight data: 36 GeV/c interacting proton

Positron selection with calorimeter

Preliminary

p (non-int)

ee--

ee++

p (non-int)

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

p (int)

p (int)

Rigidity: 20-30 GV

Positron 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

Preliminary

Positron 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

Preliminary

Positron selection with calorimeter

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

Positron 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

Positron to Electron Fraction Prelim

inary!!!

End 2007: ~20 000 positrons total

Charge sign dependent solar modulation

Positrons with HEAT Positrons with HEAT

Kinetic Energy (GeV)

Flu

x (p

/cm

^2 s

r s)

Proton flux July 2006

Galactic H and He spectraGalactic H and He spectraPrelim

inar

y !!!

ChallengesChallenges

Solar Modulation at low energiesSolar Modulation at low energies

Charge-sign dependence of solar Charge-sign dependence of solar modulationmodulation

Background calculationBackground calculation

Solar Modulation of galactic Solar Modulation of galactic cosmic rayscosmic rays

BESS

Caprice / Mass /TS93AMS-01

Pamela

Continuous Continuous monitoring monitoring of solar activityof solar activity

Study of charge sign Study of charge sign

dependent effectsdependent effects Asaoka Y. et al. 2002, Phys. Asaoka Y. et al. 2002, Phys.

Rev. Lett. 88, 051101), Rev. Lett. 88, 051101), Bieber, J.W., et al. Physi-cal Bieber, J.W., et al. Physi-cal

Review Letters, 84, 674, Review Letters, 84, 674, 1999. 1999.

J. Clem et al. J. Clem et al. 30th ICRC 30th ICRC

20072007

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

Charge sign dependence of cosmic Charge sign dependence of cosmic ray modulation. ray modulation.

Two systematic deviations from reflection symmetry of the Two systematic deviations from reflection symmetry of the interplanetary magnetic field:interplanetary magnetic field:

1) The Parker field has opposite magnetic polarity above and 1) The Parker field has opposite magnetic polarity above and below the equator, but the spiral field lines themselves are below the equator, but the spiral field lines themselves are mirror images of each other. This antisymmetry produces mirror images of each other. This antisymmetry produces drift velocity fields that for positive particles converge on the drift velocity fields that for positive particles converge on the heliospheric equator in the Aheliospheric equator in the A++ state or diverge from it in A state or diverge from it in A- -

state.state. Negatively charged particles behave in the opposite manner Negatively charged particles behave in the opposite manner

and the drift patterns interchange when the solar polarity and the drift patterns interchange when the solar polarity diverge.diverge.

2) Systematic ordering of turbulent helicity can cause 2) Systematic ordering of turbulent helicity can cause diffusion coefficients to depend directly on charge sign and diffusion coefficients to depend directly on charge sign and polarity state. polarity state. Bieber, J.W., et al. Phys. Rev. Letters, 84, 674, Bieber, J.W., et al. Phys. Rev. Letters, 84, 674, 1999. 1999.

Radiation BeltsRadiation Belts

South Atlantic AnomalySouth Atlantic Anomaly

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

Pamela maps at various Pamela maps at various altitudesaltitudes

PRELIMINARY !!!!

Altitude scanning

Primary and Albedo (sub-cutoff Primary and Albedo (sub-cutoff measurements)measurements)

Size of SAA for altitudes between 350-600kmSize of SAA for altitudes between 350-600km

Altitudes changes from 350 to 600km Longitude

Lat

itu

de

B<0.21Gs, L-shell <1.2

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

ee++/e/e-- ratio in the equatorial ratio in the equatorial region region

(L<1.2, B>0.25)(L<1.2, B>0.25)

0,01 0,1 1 100,1

1

10

Fe+/F

e-

E, GeV

PAMELA AMS MARIA

Differential energy spectra of Differential energy spectra of secondary electron and positron secondary electron and positron

fluxes at the geomagnetic fluxes at the geomagnetic equator (L<1.2, B>0.25)equator (L<1.2, B>0.25)

0,01 0,1 1 10

1E-6

1E-5

1E-4

1E-3

0,01

0,1

1

10

Flu

x, (m

2*s

ec*M

eV*s

r)-1

E, GeV

electrons PAMELA positrons PAMELA electrons AMS positrons AMS electrons MARIA positrons MARIA

Flu

x (a

.u.)

December 2006 Solar particle eventsDecember 2006 Solar particle events

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

December 13th 2006 eventDecember 13th 2006 event

Preliminary!

Preliminary!

December 13th 2006 He differential spectrumDecember 13th 2006 He differential spectrum

Diffusion Halo ModelDiffusion Halo Model

Flight data: 14.7 GVInteracting nucleus

(Z = 8)

Secondaries / primaries Secondaries / primaries i.e. Boron/ Carbon to constrain propagation parametersi.e. Boron/ Carbon to constrain propagation parameters

D. Maurin, F. Donato R. Taillet and P.Salati ApJ, 555, 585, 2001 [astro-ph/0101231]

F. Donato et.al, ApJ, 563, 172, 2001 [astro-ph/0103150]

AstrophysicAstrophysicB/CB/C

constraintsconstraints

Nuclear Nuclear cross cross

sections!!sections!!

B/C Ratio Antiproton flux

B/C selected experimentsB/C selected experiments

Preliminary Results B/CPreliminary Results B/CPreliminary

Helium and Hydrogen Helium and Hydrogen IsotopesIsotopes

Secondary to Primary Secondary to Primary ratiosratios

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

uuddss

ssdd

ddss

ssuudd

uudduuuudddd

ssuussuuuudd

dd dd dddd dd

uuuu

uuuu

ssuu ss

ssss

dddd uu

uuuudd

uuuudd

dddd uu

uuuudd

dddd uu dddd uu dddd uudddd uu

uuuudd uuuudd

uuuudd

p n

AMS courtesy

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

MANY THANKS!MANY THANKS!

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