Cosmic Ray Study The PAMELA Experiment Piergiorgio Picozza INFN and University of Rome Tor Vergata 23 rd European Cosmic Ray Symposium Moscow, Russia July 3 – 7, 2012

PAMELA Payload for Antimatter Matter Exploration and Light Nuclei Astrophysics

PAMELA Launch 15/06/06 70° inclination Km altitude since 2011: 500 Km 16 Gigabytes trasmitted daily to Ground NTsOMZ Moscow

PAMELA Collaboration Moscow St. Petersburg Russia: Sweden: KTH, Stockholm Germany: Siegen Italy: BariFlorenceFrascatiTriesteNaplesRome CNR, Florence

PAMELA Instrument GF ~21.5 cmsr GF ~21.5 cm 2 sr Mass: 470 kg Size: 130x70x70 cm Size: 130x70x70 cm 3

Bending in spectrometer: sign of charge Ionisation energy loss (dE/dx): magnitude of charge Interaction pattern in calorimeter: electron-like or proton-like, electron energy Time-of-flight: trigger, albedo rejection, mass determination (up to 1 GeV) Positron (NB: p/e + ~ ) Antiproton (NB: e - /p ~ 10 2 ) Antiproton / Positron Identification

PAMELA Cosmic Ray Spectra

e-e-

Proton and Helium fluxes p He Science 332,69 (2011)

Proton and Helium fluxes

Proton Flux

Helium Flux

Proton to Helium ratio

Proton and Helium fluxes PAMELA

2 H 3 He

2 H/ 1 H 3 He/ 4 H4

Boron and Carbon nuclei Spectra Carbon Boron

Lithium Preliminary Results

Beryllium Preliminary Results

Antiparticles with PAMELA

THE UNIVERSE ENERGY BUDGET

DM annihilations DM particles are stable. They can annihilate in pairs. Primary annihilation channels Decay Final states σ= σ a =

Antiproton Flux (0.06 GeV – 250 GeV) Ptuskin et al. (ApJ 642 (2006) 902) Donato et al. (ApJ 563 (2001) 172)

Antiproton to proton ratio (0.06 GeV GeV) Donato et al. (PRL 102 (2009) ) Simon et al. (ApJ 499 (1998) 250)Ptuskin et al. (ApJ 642 (2006) 902) PRL 102, (2009) and PRL. 105, (2010)

Antiproton to proton flux ratio new data

Positron to Electron Fraction (2 GeV – 300 GeV) GALPROP

Phys. Rev. Lett. 106, (2011) PAMELA Electron flux

Positron Flux

A Challenging Puzzle for Dark Matter Interpretation

Phys.Rev.D8:103520,2008 Phys.Rev.D79:103529,2009

Electron Spectrum e + + e - e-e- Flux=A E -   = 3.18 ±0.05

Fermi ( e + + e - ) and PAMELA ratio Bergstrom et al. Phys.Rev.Lett.103:031103,2009

All electrons

35 A NEUTRON STAR WITH A STRONG MAGNETIC FIELD: FAST ROTATING PULSAR (P = 33 msec) L(spindown) = erg/s

Mirko Boezio, LHC & DM Workshop, 2009/01/06 Example: pulsars H. Yüksel et al., arXiv: v2 Contributions of e- & e+ from Geminga assuming different distance, age and energetic of the pulsar Hooper, Blasi, and Serpico arXiv:

A Challenging Puzzle for CR Physics P.Blasi, PRL 103 (2009) ; 4 Positrons (and electrons) produced as secondaries in the sources (e.g. SNR) where CRs are accelerated. S: Sarkar Phys.Rev.Lett.103:081104,2009 arXiv: Nearby sources But also other secondaries are produced: significant increase expected in the p/p and B/C ratios. Y. Fujita Phys.Rev.D80:063003,2009 N.J. Shaviv et al., PRL 103 (2009) ;

Solar Modulation of galactic cosmic rays BESS Caprice / Mass /TS93 AMS-01 Pamela Study of solar modulation Study of charge sign dependent effects Asaoka Y. et al. 2002, Phys. Rev. Lett. 88, ), Bieber, J.W., et al. Physi-cal Review Letters, 84, 674, J. Clem et al. 30th ICRC 2007 U.W. Langner, M.S. Potgieter, Advances in Space Research 34 (2004)

Cosmic-Ray Antiprotons and DM limits D. G. Cerdeno, T. Delahaye & J. Lavalle, arXiv: 1108:1128 Antiproton flux predictions for a 12 GeV WIMP annihilating into different mass combinations of an intermediate two-boson state which further decays into quarks. See also: M. Asano, T. Bringmann & C. Weniger, arXiv: M. Garny, A. Ibarra & S. Vogl, arXiv: R. Kappl & M. W. Winkler, arXiv:

Secondary production Moskalenko & Strong 98 PAMELA Positron Fraction GALPROP Preliminary Mirko Boezio, Innsbruck, 2012/05/29

Galactic proton and helium modulation H He

Galactic proton modulation Time protons

positrons electrons positrons

Galactic proton modulation – flux evolution in time

December 2006 Solar particle events Dec 13 th largest CME since 2003, anomalous at sol min

December 13th 2006 event Preliminary!

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

December 14th 2006: Forbush decrease 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

Forbush decrease – protons

Forbush decrease – protons and electrons

Forbush decrease – protons, electrons and positrons

2012

Subcutoff particles and South Atlantic Anomaly

The discovery of geomagnetically trapped antiprotons O. Adriani et al., APJL 737 L29 (2011)

The geomagnetically trapped antiproton-to-proton ratio measured by PAMELA in the SAA region (red) compared with the interplanetary (black) antiproton-to-proton ratio measured by PAMELA, together with the predictions of a trapped model. The discovery of geomagnetically trapped antiprotons

Subcutoff particle spectra --- M. Honda, 2008

Subcut-off electrons and positrons e-e- e+e+

Stably trapped Quasi trapped Reentrant albedo  eq vs L-shell B/B eq vs L-shellGeo. Lat vs Long Distributions of sub-cutoff proton counts

Proton gradients in the heliosphere – PAMELA and Ulysses

Comparison of the proton flux measured between 1.6 and 1.7 GV by PAMELA and ULYSSES as a function of time Proton gradients in the heliosphere – PAMELA and Ulysses ASTRA 7, 425 – 434 (2011)

Proton gradients in the heliosphere – PAMELA and Ulysses Radial gradient Latitudinal gradient

Summary of PAMELA results

Thanks! pamela.roma2.infn.it

A > 0 Positive particles A < 0 ¯ + ¯ + Pamela 2006 (Preliminary!) Charge dependent solar modulation