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
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dd dd dddd dd
uuuu
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dddd uu
uuuudd
dddd uu dddd uu dddd uudddd uu
uuuudd uuuudd
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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