Results of the PAMELA Space Mission

Results of the

PAMELA Space Mission

Benasque, 12 February 2009 XXXVII International Meeting on Fundamental Physics,

Piero Spillantini

University and INFN, Florence, Italy

(on behalf of Pamela collaboration)

COSMIC RAYS:

from far away, .... at high speed...

ANTIMATTER:

measuring antiparticles and hunting for antinuclei

WIZARD on Astromag ballooning

Russian Italian Mission program PAMELA PAMELA:

the choices the detectors the results

the future and ... the competition

Summary

19-th century:

- discovery of electricity

- acceleration of the electrons

- production of X-rays Energy up to few KeV

End of 19-th century

- discovery of natural radioactivity Energy up to few MeV Beginning of 20-th century:

- access to high atmosphere

- discovery of Cosmic Rays Energy up to many GeV

Years 60’s of 20-th century:

- access to space Astrophysics

Years 70’s of 20-th century:

- permanent presence in space

The Great Observatories and the Freedom Space Station

Particle Physics Second half of 20-th centuries

- accelerators reach CR energies

International Space Station

“FREEDOM”

Hubble

Space

Telescope

Space Station “FREEDOM” (1983)

CGRO AXAF (CXO+

XMM)

HST SIRTF

Heavy Nuclei Collector (HNC) and

Particle-Antiparticle Superconducting Magnet

(ASTROMAG) facilities

on board of the Freedom SS

+

Very Long Base Interferometer

(VLBI)

+

Advanced Composition

Explorer (ACE)

1991 1990 2002

1999

1999

CA NC EL LE D

High Z

Light Elements and Isotopes

Antiparticles and Antinuclei

Elemental Composition

Extreme Energy CR

[AUGER, EUSO, TUS/KLYPVE]

Direct detection Balloons &

Satellites

Indirect detection (EAS) [arrays & florescence]

Cosmic Rays from Space

(JEM-,S-) EUSO, TUS, KLYPVE,

OWL

ISTP/

HNC

WIND

A.C.E .

ASTROMAG

BESS, PAMELA,

AMS AGILE, GLAST

ENTICE, ECCO Cut-off

momentum

Antimatter on a Cosmological scale?

• Fundamental question (on 30’s to 60’s):

how can the Universe contain equal amounts of M and antiM ??

Problem of separating M and antiM on large scale

Big Bang models

based on statist. fluct.

M

< 10

M

#Baryon / #Photon ≈ 10

#Baryon / #Photon ≈ 1 @ t ≤ 10

s

#Baryon / #Photon ≈ 10

now

1964: CP violation in nature

1967: Sakharov’s conditions to achieve baryon asymmetry in the Early Universe:

(1) Baryon decay allowed (2) CP violation allowed

(3) A period out of equilibrium

The three Sakharov’s conditions:

• allow the possibility of an “all Matter” Universe

CP built in the Lagrangian

but also:

• offer a solution to the Matter-antiMatter separation problem in a Baryon Symmetric Universe

CP is spontaneous

there are DOMAINS with either Matter or antiMatter inflaction can increase these DOMAINS to

astronomical scale

(indirect observation)

high energy

( 100 GeV/n)

(direct observation)

--- Experimental summary (<2008):

•••• The “MeV bump” disappeared (in 1995)

•The p

and e

measured fluxes can be justified

by production on ISM

•••• The search for N

gave only upper limits

--- AT PRESENT (<2008):

NO EXPERIMENTAL INDICATIONS FOR COSMOLOGICAL ANTIMATTER --- NEEDED:

--- WHAT FOR THE NEXT FUTURE?? : HIGHER ENERGIES (for p-, e+, N-)

CLEANER ENVIRONMENT (p-, e+ in space)

BESS by LDB flights (p- exotic, N-) going on

PAMELA on satellite (p-, e+, N-) flown middle 2006

AMS-02 on ISS (N-, p-, e+) to be flown in 2010

AntiM. ‘ideal scheme’

payload services He

Air Air

Class A balloons 2.8 Mm

@ 5 g/cm

Lifting power ~ 11t Balloon 5 t

services 3 t

payload 3 t @ 38÷40km (5g/cm

residual atm.)

Open balloons

Atmospheric temperature versus Altitude

Km

0 C°

-100 40

0

4-5 g/cm2 residual atmosphere

‘open’ balloons:

Volume @ 5g/cm 2 > 1 Mm 3 Very thin material (20µm),

does not support pressure differences Maximum load ≈ 3 t

Line of sight (LOS) ≈ 800 km

Tipical duration of the flight 20 hours

Maximum altitude ≈ 40 km (4÷5g/cm 2 ) Background

> signal

Limited

Statistics

New Generation of

Antimatter Researches in Cosmic Rays

[BESS + PAMELA + AMS-2]

It is necessary a:

PAMELA

Experiments approved for the first phase of the

ASTROMAG facility

from WIZARD to PAMELA

WiZard: Russian Italian Missions (RIM)

…1989 · 1990 · 1991 · 1992 · 1993 · 1994 · 1995 · 1996 · 1997 · 1998 · 1999 · 2000 · 2001 · 2002 · 2003 · 2004 · 2005 · 2006 · 2007..

PAMELA

NINA-1 NINA-2 SILEYE-1

SILEYE-2

Alteino-SILEYE-3

ALTEA-SILEYE-4 M 89•

M 91•

TS 93• C 94•

C 97•

C 98•

SILEYE-2

SILEYE-1 ALTEINO:

SILEYE-3 ALTEA:

SILEYE-4 LAZIO

SIRAD MASS-89, 91, TS-93,

CAPRICE 94-97-98

NINA-2

NINA-1 PAMELA

LAZIO-SIRAD

  

 Antimatter search Life Science

Solar physics

Balloon exp’s MASS (89) MASS1(91)

TS93 (93) CAPRICE (94) CAPRICE (97) CAPRICE (98)

Low En. C.R.

in orbit NINA (98) NINA2 (00)

Life Science on MIR and ISS SIL-EYE-1 (95)MIR SIL-EYE-2 (97) MIR

SIL-EYE-3 (02) ISS ALTEA (05) ISS

PAMELA Background

O. Adriani¹, M. Ambriola², G.Barbarino¹⁶, L.M. Barbier⁴, G. Bazilevskaja⁶, R. Bellotti², D.

Bergstrom⁷, M. Boezio³, E. Bogomolov¹⁰, V. Bonvicini³, M. Boscherini¹, F. Cafagna², P. Carlson⁷, M.

Casolino⁸, G. Castellini¹⁵, E.R. Christian⁴, M. Circella², R. D’Alessandro¹, C.N. De Marzo², M.P. De Pascale⁹, G. Furano⁹, A.M. Galper¹¹, A. Grigorjeva⁶, P. Hansen⁷, S.V. Koldashov¹¹, M.G. Korotkov¹¹,

J.F. Krizmanic⁴, S. Krutkov¹⁰, A. Iannucci⁹,B. Marangelli², A. Menicucci⁹, W. Menn¹², V.V.

Mikhailov¹¹, M. Minori⁹, N. Mirizzi², J.W. Mitchell⁴, E. Mocchiutti⁷, A.A. Moiseev¹¹, A. Morselli⁹, R.

Mukhametshin⁶, J.F. Ormes⁴, G.Osteria¹⁶, P. Papini¹, G. Percossi⁹, P. Picozza⁹, M. Ricci⁵, P. Schiavon³, M. Simon¹², R. Sparvoli⁹, P. Spillantini¹, P. Spinelli², S.A. Stephens¹³, S.J. Stochaj¹⁴, Y. Stozhkov⁶, R.E.

Streitmatter⁴, F. Taccetti¹⁵, A. Vacchi³, E. Vannuccini¹, G. Vasiljev¹⁰, S.A. Voronov¹¹, N. Weber⁷, R.

Wischenwksi⁹,Y. Yurkin¹¹, N. Zampa³, GL. Zampa³

1University and INFN, Firenze (Italy)

2University and INFN, Bari (Italy)

3 University and INFN, Trieste (Italy)

4NASA Goddard Space Flight Center Greenbelt (USA)

5Laboratori Nazionali INFN, Frascati (Italy)

6Lebedev Physical Institute (Russia)

7Royal Institute of Technology, Stockholm (Sweden)

8 Electronic Engineering Department, II University, Roma-Tor Vergata (Italy)

9II University and INFN, Roma-Tor Vergata (ltaly)

10Ioffe Physical Technical Institute (Russia)

11 Moscow Engineering and Physics Institute, Moscow (Russia)

12 Siegen University, Physics Department, Siegen (Germany)

13 Tata Institute of Fundamental Research, Bombay (India)

14 Particle Astrophysics Laboratory, NMSU, Las Cruces (USA)

15 Istituto di Ricerca Onde Elettromagnetiche CNR, Firenze (Italy)

16 University and INFN, Napoli (Italy)

( ∆ R=R)

Max antip E (40) (60) (80) (150)

Neutron Detector

5 magnets, 4.8 kG @ center

•••• IMAGING (2.4mm granularity)

•••• 16 Xo deep

• 44 Si layers + W

•••• 4.4 kchannels Scintillation

Counters Hodoscopes

2 layers 2 layers

2 layers 1 layer

9 counters

36 He3 counters

MASS = 480 kg POWER = 345 W

GF = 20.5 cm2sr MDR = 740 GV/c

Si µµ-strip, double side, µµ double metallization

•6 planes x 6 sensors

••••37 kchannels

Readout pitch 50µ Resolution <3µ

Granularity 2 x 2 x 4 mm

PAMELA

Positrons 50 MeV - 270 GeV Antiprotons 80 MeV – 190 GeV

Limit on antinuclei ~7 10

(He /He)

Electrons 50 MeV – 2TeV Protons 80 MeV – 700 GeV Nuclei < 300 GeV/n (Z ≤ 8) study of the solar modulation

after the 23

solar cycle maximum.

GF 20.5 cm

sr Mass 480 Kg

Dimensions 120 x 40x45 cm

Power Budget 345W

PAMELA milestones

• Launch from Baikonur: June 15

2006, 0800 UTC.

• Power On: June 21

2006, 0300 UTC.

• Detectors operated as expected after launch

• PAMELA in continuous data-taking mode since commissioning phase ended on July 11

2006

• As of ~ now:

• • ~600 days of data taking (~73% live-time)

• ~10 TByte of raw data downlinked

• >10

triggers recorded and under analysis

Mirko Boezio, INFN Trieste

Mirko Boezio, INFN Trieste --ICHEP08, 2008/08/01ICHEP08, 2008/08/01

32.3 GV

positron

36 GeV/c

interacting proton

Antiprotons

Search of structures in antiproton spectrum

Secondary production (upper and lower limits) Simon et al.

Secondary production (CAPRICE94-based) Bergström et al.

Primary production from χχ

χχ χχ

χχ annihilation (m(χχχχ) = ~ 1 TeV)

( astro-ph 9904086)

Pamela expectation

Antiproton identification

e

(+ p-bar)

p-bar

p -1 ← ← ← ← Z → → → → +1

“spillover” p

p (+ e

)

proton-consistency cuts (dE/dx vs R and ββββvs R)

electron-rejection cuts based on calorimeter-pattern topology

1 GV 5 GV

( For |Z|=1, deflection=1/p )

p-bar “spillover” p p

10 GV 50 GV

Proton-spillover background

MDR = 1/σ σ σ σ

(evaluated event-by-event by the fitting routine)

R < MDR/10

MDR depends on:

• number and distribution of fitted points along the trajectory

• spatial resolution of the single position measurements

• magnetic field intensity along the trajectory

Antiproton-to-proton ratio

astro-ph 0810.4994

PRL 102 (2009)

*preliminary*

(Petter Hofverberg’s PhD Thesis)

Antiproton-to-proton ratio

Secondary Production Models

(Donato et al. 2001)

•Diffusion model with convection and reacceleration

• Solar modulation: spherical model (f=500MV )

→Uncertainty band related to propagation parameters (~10%

@10GeV)

→Additional uncertainty of ~25% due to production cs should be considered !!

(Ptuskin et al. 2006) GALPROP code

•Plain diffusion model

• Solar modulation: spherical model ( f=550MV ) (Moskalenko et al. 2006) GALPROP code

•Plain diffusion model

• Solar modulation: drift model ( A<0, α=15^o )

CR + ISM → p-bar + …

Antiproton-to-proton ratio

Secondary Production Models

No evidence for any antiproton excess

•Solar modulation

…

CR + ISM → p-bar + …

~20%

Positrons

arXiv:0810.4995v1 [astro-ph] 28 Oct 2008 Accepted on Nature

Pamela e+ results

•Till August 30

about 20000 positrons from 200 MeV up to 200 GeV have been

analyzed

•More than 15000 positrons over 1 GeV

•Other eight months data to be analyzed

(Moskalenko &

Strong 1998) GALPROP code

• Plain diffusion model

• Interstellar spectra

arXiv:0810.4995v1 [astro-ph] 28 Oct 2008 Accepted on Nature

Pamela e+ results

Positrons to Electrons ratio

___ Moskalenko & Strong 1998

statistical errors only

Pr eli m

in ar y

¯

Charge sign +

dependent

solar

modulation

(Moskalenko &

Strong 1998) GALPROP code

• Plain diffusion model

• Interstellar spectra

Positron fraction

Secondary Production Models CR + ISM → π

+ … → µ

+ … → e

+ …

CR + ISM → π

+ … → γγ → e

Positron fraction

Secondary Production Models

(Moskalenko &

Strong 1998) GALPROP code

• Plain diffusion model

• Interstellar spectra

(Delahaye et al. 2008)

• Plain diffusion model

• Solar modulation: spherical model (φ=600MV)

→Uncertainty band related to e^-spectral index (γγγγ_e= 3.44±0.1 (3σ)⇒ MIN÷MAX)

→Additional uncertainty due to propagation parameters should be considered

soft hard

CR + ISM → π

+ … → µ

+ … → e

+ …

CR + ISM → π

+ … → γγ → e

Positron fraction

Secondary Production Models

soft hard

Quite robust evidence for a positron excess

Primary positron sources

Dark Matter

• e

yield depend on the dominant decay channel

→ LSPs seem disfavored due to suppression of e

e

final states

→ low yield (relative to p-bar)

→ soft spectrum from cascade decays

→LKPs seem favored because can annihilate directly in e

e

→ high yield (relative to p-bar)

→ hard spectrum with

pronounced cutoff @ M

(>300 GeV)

LKP -- M= 300 GeV

(Hooper & Profumo 2007)

Primary positron sources

Astrophysical processes

• Local pulsars are well- known sites of e

e

pair production:

→ they can individually and/or coherently contribute to the e

e

galactic flux and explain the PAMELA e

excess (both spectral feature and intensity)

→ No fine tuning required

→ if one or few nearby pulsars dominate, anisotropy could be detected in the angular

distribution

→ possibility to discriminate

between pulsar and DM origin of e

excess

All pulsars (rate = 3.3 / 100 years) (Hooper, Blasi, Serpico 2008)

(Chang et al 2008)

PAMELA positron excess might be connected with ATIC

electron+positron structures

Primary positron sources

PAMELA positron fraction alone insufficient to understand the origin of

positron excess

Additional experimental data will be provided by PAMELA:

– e

fraction @ higher energy (up to 300 GeV)

– individual e

e

spectra – anisotropy (…maybe)

– high energy e

+e

spectrum (up to 2 TV)

Complementary information from:

– gamma rays

– neutrinos

Cosmic-ray antimatter search

BESS combined (new) expected

Galactic cosmic-ray origin &

propagation

PAMELA: Galactic H and He spectra

Pre lim

ina ry ! !!

Pre lim

ina ry ! !!

Pre lim

ina ry ! !!

Pre lim

ina ry ! !!

Very high statistics on a very wide energy range - Precise measurement of spectral shape

- Possibility to study time variations and transient phenomena

•Local spectrum:

injection spectrum ⊗⊗⊗⊗ galactic propagation

Local primary spectral shape:

⇒ study of particle acceleration mechanism

Power Power Power

Power----law fit: ~ Elaw fit: ~ Elaw fit: ~ Elaw fit: ~ E^----γγγγ γ

γ γ

γ ~ 2.76

still large discrepancies among different primary

flux measurements

(statistical errors only)

Proton flux

esc P

P

Q λ

N ∝

Secondary nuclei

• B nuclei of secondaryorigin:

CNO + ISM → B + …

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

Local secondary abundance:

⇒ study of galactic CR propagation

(B/C used for tuning of propagation models)

S P esc

P

S

λ σ

N N

⋅

∝

PAMELA: Proton Spectra PAMELA: Proton Spectra

RED: JULY 2006 BLUE: AUGUST 2007

P /( cm ^ 2 s r G eV s )

Pre lim

ina ry Pre lim

ina ry Pre lim

ina ry Pre lim

ina ry

Interstellar spectrum

July July

July July 2006 2006 2006 2006 August August August

August 2007 2007 2007 2007 February February February

February 2008 2008 2008 2008 D e c re a si n g D e c re a si n g D e c re a si n g D e c re a si n g so la r a c tiv ity so la r a c tiv ity so la r a c tiv ity so la r a c tiv ity In c re a si n g In c re a si n g In c re a si n g In c re a si n g G C R fl u x G C R fl u x G C R fl u x G C R fl u x

Solar modulation

(statistical errors only)

Proton spectrum in SAA, polar and equatorial regions

Proton spectrum in SAA, polar and equatorial regions

RED: JULY 2006

BLUE: AUGUST 2007

P /( cm ^ 2 s r G eV s )

Secondary particles (reentrant albedo)

Penumbra

Primary and secondary spectra:

Magnetic equator

RED: JULY 2006

BLUE: AUGUST 2007

P /( cm ^ 2 s r G eV s )

Primary and secondary spectra:

Intermediate latitudes

Secondary particles (reentrant albedo)

Penumbra

p

e e

p

A look at Earth:

the geomagnetic field

SAA

Trapped

Galactic

Spectrum of proton radiation belt inside the SAA

B < 0.19 G

0.19 G ≤ B < 0.20 G 0.20 G ≤ B < 0.21 G B > 0.30 G

0.22 G ≤ B < 0.23 G 0.21 G ≤ B < 0.22 G

Always: 10 GV < cutoff < 11

(statistical errors only)

Solar Physics

Solar CR prpagation

Solar Energetic Particle events (SEPs)

80 MeV

50 MeV

Proton detection threshold

Electron detection threshold

-Solar modulation effects

-High energy component of Solar

Proton Events (from 80 Mev to 10 GeV) -High energy component of e- and e+

in Solar Events (from 50 MeV) + Nuclear composition of

Gradual and Impulsive Events

+ He isotopic composition

Pr eli mi na ry ! December 13th 2006 event

December 13th 2006 event

• PAMELA is measuring the Antiprotons and Positrons to the high energies (> 150GeV) with an unprecedented statistical precision

• PAMELA is setting a new lower limit for finding Antihelium

• PAMELA is looking for Dark Matter candidates

• PAMELA is providing measurements on elemental spectra and low mass isotopes with an unprecedented statistical precision and is helping to improve the understanding of particle propagation in the interstellar medium

• PAMELA is able to measure the high energy tail of solar particles.

For the future (other >2 years data):

Fluxes of e+ ( ≤ 300GeV), e- ( ≤ 500 GeV, ≤ 2TeV), p ( ≤ 700GeV) Fluxes of light nuclei (up to O) and light isotopes

Monitoring of solar activity by SEP measurement

Anomalous CR (??), Jovian e- (?)

BESS

BESS BESS

Balloon-borne

Experiment with a Superconducting Spectrometer

Search for

Primordial Antiparticle

antiproton: Novel primary origins (PBH,DM) antihelium: Asymmetry of matter/antimatter

Precise Measurement of Cosmic-ray flux:

highly precise measurement at < 1 TeV

PAMELA

AMS-2

Cosmic-ray antimatter search

BESS combined (new) expected

AMS-2 on ISS

AMS

Altezza: 320

Altezza: 320 - - 390 Km 390 Km Inclinazione 51.7

Inclinazione 51.7 ° °

Taiwan CSIST NCU Academia Sinica NSPO

Korea IHEP Helsinki

Turku Aarhus

Ciemat-Madrid LIP-Lisbon MIT

Yale Johns Hopkins Maryland Florida A&M Mexico

Bologna Milano Perugia Pisa Roma Siena Annecy

Grenoble Montpellier

IEE, IHEP Jiao Tong University Southeast University ESA

NIKHEF NLR, Amsterdam

ETH-Zurich Geneva Univ.

Kurchatov Inst.

Inst. of Theor. & Experimental Physics Moscow State Univercity Achen I & III

Karlsruhe Munich Bucharest

AMS AMS - - 02 on ISS 02 on ISS In Orbit 2009 In Orbit 2009

TRD

RICH

Vacuum Case

Tracker

MAGNET He Vessel

The Completed AMS Detector on ISS The Completed AMS Detector on ISS

Transition Radiation Detector (TRD)

Silicon Tracker

Electromagnetic Calorimeter (ECAL)

Magnet

Ring Image Cerenkov Counter (RICH)

Time of Flight Detector (TOF)

Size: 3m x 3m x 3m

Weight: 7 tons

Pamela and AMS-02

Space Observatories at 1AU

Jovian electrons

Anomalous Nuclei Nearby e

Sources

Magnetospheric physics Solar Modulation

Solar Energetic particles Matter : Antimatter

PBH Dark Matter Galactic cosmic rays

R. B., SAA, Albedo,

secondary particle

Atmosphere 23 Xo

40 km

Extended Air Shower

Particle

Astrophysics Experiments

(further acceleration?)

Propagation (through Galaxy)

SIRFT CGRO

AXAF(CXO) HST

VLBI

γγγγ

Modulation (through Heliosphere)

γγγγ

ν

Cosmic Ray

creation acceleration injection

Direct detection

Underground, Under-ice, Underwater Cosmic rays:

about 10 Myears in the Galaxy (6-7 g/cm²)

Thank you for your attention

Gracias por su atencion!