pamela space mission first results in cosmic rays

PAMELA Space MissionPAMELA Space Mission

First Results in Cosmic Rays First Results in Cosmic Rays

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

Pamela CollaborationPamela Collaboration

Rencontres de Blois 2008Rencontres de Blois 2008Challenges in Particle AstrophysicsChallenges in Particle Astrophysics

Blois, May 22, 2008

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 as a Space Observatory at 1AU

Study of solar physics and solar modulation

Study of terrestrial magnetosphere

Search for dark matter annihilation

Search for antihelium (primordial antimatter)

Search for new Matter in the Universe (Strangelets?)

Study of cosmic-ray propagation

Study of high energy electron spectrum (local sources?)

Sign of charge, rigidity, dE/dx

Electron energy, dE/dx, lepton-hadron

separation

e- p -

e+ p (He,...)

Trigger, ToF, dE/dx

- +

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)

• Lifetime >3 years (assisted)

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 Orbit

Flight data: 0.169 GV electron

Flight data: 0.171 GV positron

Flight data: 0.632 GeV/cantiproton annihilation

Flight data: 84 GeV/c interacting antiproton

Flight data: 92 GeV/cpositron

Flight data: 14.7 GVInteracting nucleus

(Z = 8)

PAMELA StatusPAMELA Status

Till 2nd of March 2008 PAMELA has Till 2nd of March 2008 PAMELA has collected ~ 8.8TB of data, collected ~ 8.8TB of data, corresponding to corresponding to ~~ 10 109 9 triggerstriggers

4% 23% 73%

(GLAST AMS-02)

Signal (supersymmetry)…

… and background

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-loopprocesses that produces monoenergeticγ γ in the final state.

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

Antiproton-Proton RatioAntiproton-Proton Ratio

Antiproton-Proton RatioAntiproton-Proton Ratio

preliminary

Antiproton-Proton RatioAntiproton-Proton Ratio

preliminary

Cirelli, Franceschini, Strumia

arXiv:0802.3378v2 [hep-ph]

Positron - Electron ratioPositron - Electron ratio

Potgieter at al. arXiv:0804.0220v1 [astro-ph]

Pamela PositronsPamela Positrons

Till August 30Till August 30thth about 20000 positrons about 20000 positrons from 200 MeV up to 200 GeV have been from 200 MeV up to 200 GeV have been analyzedanalyzed

More than 15000 positrons over 1 GeVMore than 15000 positrons over 1 GeV

Other eight months data to be analyzedOther eight months data to be analyzed

Positron - Electron ratioPositron - Electron ratio

PAMELA

Preliminary

Positron - Electron ratioPositron - Electron ratio

Positron - Electron ratioPositron - Electron ratioPrelim

inary

Positrons with HEAT Positrons with HEAT

Positrons with HEAT & PAMELA Positrons with HEAT & PAMELA Prelim

inary

ProblemsProblems

Background calculationBackground calculation

Solar Modulation at low energiesSolar Modulation at low energies

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

Diffusion Halo ModelDiffusion Halo Model

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

Preliminary Results B/CPreliminary Results B/CPreliminary

Helium and Hydrogen IsotopesHelium and Hydrogen Isotopes

Secondary to Primary ratiosSecondary to Primary ratios

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 !!!

Solar Physics with PAMELASolar Physics with PAMELA

Solar Modulation of galactic cosmic raysSolar Modulation of galactic cosmic 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

Antiproton-Proton RatioAntiproton-Proton Ratio

preliminary

Proton SpectraProton SpectraPrelim

inar

y !!!

RED: JULY 2006BLUE: AUGUST 2007

P/(

cm^2

sr

GeV

s)

Primary spectrum 2222is MφE+/ME F =F

July 2006 497±2January 2007 481±2August 2007 441±2

BESS Coll. 30th ICRC 2007

Positron FractionPositron Fraction

Mirko Boezio, INFN Trieste - Fermilab, 2008/05/02Mirko Boezio, INFN Trieste - Fermilab, 2008/05/02

Preliminary

Clem at al. 30th ICRC 2007

Pamela Pamela

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

December 2006 Solar particle eventsDecember 2006 Solar particle events

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

December 13th 2006 event

Preliminary!

Preliminary!

December 13th 2006 He differential 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

Pamela World Maps: 350 – 650 km altPamela World Maps: 350 – 650 km alt

36 MeV p, 3.5 MeV e-

Pamela maps at various altitudesPamela maps at various altitudesPRELIMINARY !!!!

Altitude scanning

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

Other ObjectivesOther Objectives

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 the Search for the existence of Antimatter in the UniverseUniverse

What about heavy antinuclei?What about heavy antinuclei? The discovery of one nucleus of antimatter The discovery of one nucleus of antimatter

(Z≥2) in the cosmic rays would have profound (Z≥2) in the cosmic rays would have profound implications for both particle physics and implications for both particle physics and astrophysics.astrophysics.

• For a Baryon Symmetric Universe Gamma For a Baryon Symmetric Universe Gamma

rays limits put any domain of antimatter rays limits put any domain of antimatter

more than 100 Mpc away more than 100 Mpc away

(Steigman (1976) Ann Rev. Astr. Astrophys., (Steigman (1976) Ann Rev. Astr. Astrophys., 1414, 339; Dudarerwicz , 339; Dudarerwicz

and Wolfendale (1994) M.N.R.A. and Wolfendale (1994) M.N.R.A. 268268, 609, A.G. Cohen, A. De Rujula , 609, A.G. Cohen, A. De Rujula

and S.L. Glashow, Astrophys. J. 495, 539, 1998)and S.L. Glashow, Astrophys. J. 495, 539, 1998)

Antimatter Direct researchAntimatter Direct research

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

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

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

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

Cosmic-ray antimatter searchCosmic-ray antimatter search

“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)

BESS combined (new)

expected

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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Search for New Matter in the Universe:

ConclusionConclusion

PAMELA is the first space experiment which is measuring PAMELA is the first space experiment which is measuring

the Antiprotons and Positrons to the high energies (> the Antiprotons and Positrons to the high energies (>

150GeV) with an unprecedented statistical precision150GeV) with an unprecedented statistical precision PAMELA is setting a new lower limit for finding AntiheliumPAMELA is setting a new lower limit for finding Antihelium PAMELA is looking for Dark Matter candidatesPAMELA is looking for Dark Matter candidates PAMELA is providing measurements on elemental spectra PAMELA is providing measurements on elemental spectra

and low mass isotopes with an unprecedented statistical and low mass isotopes with an unprecedented statistical

precision and is helping to improve the understanding of precision and is helping to improve the understanding of

particle propagation in the interstellar mediumparticle propagation in the interstellar medium PAMELA is able to measure the high energy tail of solar PAMELA is able to measure the high energy tail of solar

particles.particles.

THANKSTHANKS

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