Antiproton and Electron Measurements

and Dark Matter Searches

Piergiorgio Picozza INFN and University of Rome Tor Vergata

8th International Workshop on Identification of Dark Matter

26-30 July 2010, Montpellier, France

THE UNIVERSE ENERGY BUDGET

DM annihilationsDM annihilationsDM particles are stable. They can annihilate in pairs.

Primary annihilation channels Decay Final states

σσa= <= <σσv>v>

e-

Robert L. Golden

Antimatter SearchAntimatter Search

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)

Cosmic Ray AntimatterCosmic Ray Antimatter

AntiprotonsPositrons

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 threshold: 5.6 GeV for the reaction

pppppp

Pre-PAMELA status

Antimatter and Dark MatterAntimatter and Dark Matter Space Missions Space Missions

PAMELA15-06-2006

AMS-022010-2011

BESS12-2007

Fermi/GLAST11-6-2008

ATIC2002 - 2007

PAMELAPAMELAPPayload for ayload for AAntimatter ntimatter MMatter atter EExploration xploration

and and LLight Nucleiight Nuclei AAstrophysicsstrophysics

PAMELA InstrumentPAMELA Instrument

PAMELAPAMELA

LaunchLaunch15/06/0615/06/06

16 Gigabytes trasmitted 16 Gigabytes trasmitted daily to Grounddaily to Ground

NTsOMZ MoscowNTsOMZ Moscow

AntiprotonsAntiprotons

Antiproton FluxAntiproton Flux (0.06 GeV - 180 GeV)(0.06 GeV - 180 GeV)

Donato et al. (ApJ 563 (2001) 172)

Ptuskin et al. (ApJ 642 (2006) 902)

Adriani et al., astro-ph 1007.0821 PRL in pressPRL in press

Systematics errors included

Antiproton to proton ratio Antiproton to proton ratio (0.06 GeV - 180 GeV)(0.06 GeV - 180 GeV)

Donato et al. (PRL 102 (2009) 071301)

Simon et al. (ApJ 499 (1998) 250) Ptuskin et al. (ApJ 642 (2006) 902)

Adriani et al., astro-ph 1007.0821 PRL in pressPRL in press

Systematics errors included

Preliminar

y

Time Dependence of PAMELA Proton FluxTime Dependence of PAMELA Proton Flux

Antiproton to proton ratioDark Matter constraints

I. Cholisastro-ph :1007.1160v1.

Antiproton to proton ratio Di Bernardo et al. astro-ph 0909.4548v3

Wino Dark Matter in a non-thermal Universe

G. Kane, R. Lu, and S. Watson

arXiv:0906.4765v3 [astro-ph.HE)

Trapped pbar

GCR

SAA

• PAMELA

• PAMELA

BESS-Polar II Launch - December 22, 2007

BESS Detector–Rigidity measurement

– SC Solenoid (L=1m, B=1T)

– Min. material (4.7g/cm2)

– Uniform field– Large acceptance

–Central tracker – (Drift chamber– ~200m

– Z, m measurement– R, --> m = ZeR 1/2-1– dE/dx --> Z

JET/IDCRigidity

TOF, dE/dx

√

BESS Polar II Observations/Expectations

Antiproton Antideuteron Antihelium(Search for PBH) (Search for PBH) (Search for Antimatter)

• Event rate ~2.5 kHz; Total events ~4.7 x 109

• Total data volume 13.5 TB (3.07 kB/event)

• Expected antiprotons ~10,000 10-20 times previous Solar minimum dataset

ECRS?

PositronsPositrons

Positron to Electron FractionPositron to Electron Fraction

Secondary production Moskalenko & Strong 98

Adriani et al, Astropart. Phys. 34 (2010) 1 arXiv:1001.3522 [astro-ph.HE]

Preliminar

y

Time Dependence of PAMELA Electron Time Dependence of PAMELA Electron (e(e--) Flux) Flux

A > 0

Positive particles

A < 0

Pamela

2006

Charge dependent solar modulation

But antiprotons in CRs are in agreement with secondary production

Uncertainties on:• Secondary production (primary fluxes, cross section)• Propagation models• Electron spectrum

A Challenging Puzzle for CR PhysicsA Challenging Puzzle for CR Physics

A Challenging Puzzle for CR PhysicsA Challenging Puzzle for CR Physics

P.Blasi, PRL 103 (2009) 051104; arXiv:0903.2794Y. Fujita arxiv .0904.5298Positrons (and electrons) produced as secondaries in the sources (e.g. SNR) where CRs are accelerated.But also other secondaries are produced: significant increase expected in the p/p and B/C ratios.

I. Cholis et al., Phys. Rev. D 80 (2009) 123518; arXiv:0811.3641v1

Contribution from DM annihilation.

D. Hooper, P. Blasi, and P. Serpico, JCAP 0901:025,2009; arXiv:0810.1527 Contribution from diffuse mature &nearby young pulsars.

ElectronsElectrons

Preliminary

Electron (eElectron (e--) Spectrum) SpectrumPrelim

inary

TalkWilliamGillard

All electronsAll electrons

ee++ + e + e--

Courtesy of Luca Baldini

All electron spectrumAll electron spectrum

96 CsI (Tl)8 layers

ATIC GLAST

HESS

All three ATIC flights are consistent

ATIC-4 with 10 BGO layers has improved e , p separation. (~4x lower background)

“Bump” is seen in all three flights.

ATIC 1+2

“Source on/source off” significance of bump for ATIC1+2 is about 3.8 sigmaJ Chang et al. Nature 456, 362 (2008)

Significance for ATIC1+2+4 is 5.1 sigma

ATIC 1+2+4

Preliminary

ATIC 1ATIC 2ATIC 4

Preliminary

Example: DM Example: DM I. Cholis et al. arXiv:0811.3641v1

I. Cholis et al. arXiv:0811.3641v1 See Neal Weiner’s talk

Fermi (Fermi (ee+++ e+ e--))

Electrons measured with Electrons measured with H.E.S.S.H.E.S.S.

Fermi (Fermi (ee+++ e+ e--) and ) and PAMELA ratioPAMELA ratioBergstrom et al. astro-ph 0905.0333v1Bergstrom et al. astro-ph 0905.0333v1

Pulsars: Most significant contribution to high-energy CRE:Nearby (d < 1 kpc) and Mature (104 < T/yr < 106) Pulsars

D. Grasso et al.

Example of fit to both Fermi and Pamela data with known (ATNF catalogue) nearby, mature pulsars and with a single, nominal choice for the e+/e- injection parameters

Fermi (Fermi (ee+++ e+ e--)) D. GrassoD. Grasso astro-ph 0912.3887

All electronsPAMELA very preliminary

Taiwan

CSISTNCUAcademia SinicaNSPO

KoreaIHEP

HelsinkiTurku

Aarhus

Ciemat-Madrid

LIP-Lisbon

MITYaleJohns HopkinsMarylandFlorida

A&MMexico

BolognaMilanoPerugiaPisaRomaSiena

AnnecyGrenobleMontpellier

IEE, IHEP

Jiao Tong UniversitySoutheast University

ESANIKHEF

NLR, Amsterdam

ETH-ZurichGeneva Univ.

Kurchatov Inst.Inst. of Theor. & Experimental Physics

Moscow State Univercity

Achen I & IIIKarlsruheMunich

Bucharest

AMS-02 on ISSAMS-02 on ISSIn Orbit Nov. 2010 – Feb. 2011In Orbit Nov. 2010 – Feb. 2011

TRD

RICH

VacuumCase

Tracker

MA

GN

ET

He V

essel

The Completed AMS Detector on ISSThe Completed AMS Detector on ISSTransition Radiation

Detector (TRD)

Silicon Tracker

Electromagnetic Calorimeter (ECAL)

Magnet

Ring Image Cerenkov Counter (RICH)

Time of Flight Detector (TOF)

Size: 3m x 3m x 3mWeight: 7 tons

AMS-02 new configurationAMS-02 new configuration

Combining searches in different channels could give (much) higher sensitiviy to SUSY DM signals

antiprotons

positrons

gamma raysanti deuterons

Unique Unique Feature Feature

of of AMSAMS

The Next FutureThe Next Future

FutureFuture

PerspectivesPerspectives

Thanks!Thanks!

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