Flux of light antimatter nuclei near Earth

1. Flux of light antimatter nuclei near Earth K.V. Protasov for AMS groupe, Laboratory for Subatomic Physics and Cosmology, Grenoble, France • Motivations • Secondary antimatter production • - antiproton production (new paramertization) • - production of : coalescence model and • microscopic approach • Propagation in interstellar medium • Conclusions

2. Motivations To explain matter-antimatter asymmetry in the univers AMS, PAMELA, BESS Primary antimatter: -Anti-stars, … - SUSY particles decay - Primordial black holes (low energy component) Secondary antimatter: interaction of cosmic rays with inerstellar gas (high energy component but…) It is important to determine a « background »

3. First estimations P.Chardonnet, J.Orloff and P.Salati Phys.Lett. B409 (1997) 313-320 • F.Donato, N.Fornengo and P.Salati Phys.Rev. D62 (2000) 043003 • Our aims: • To improve predictions for the cross sections of antimatter production • To study antideutron spectrum at low energies

4. Parametrization of antiproton spectrum Quite good experimental information but only a few parametrizations (hardly valid in a large cinematic and atomic number domain) R.P. Duperray, C.Y. Huang. K.V.Protasov and M.Buénerd Phys. Rev D 68, 094017 (2003) 654 compatible experimental points

5. Light antinuclei production in p-p and p-A collisions • Standart coalescence model Projectile Fragment Target The (anti) nucleons can coalesce to form a fragment if their relative momentum is smaller than a certain quantity , (coalescence momentum) is a free parameter to be fitted from the data

6. 34 compatibles experimental points

7. LPCC, 5 Décembre 2003 Antimatière secondaire galactique • Microscopic coalescence model: diagramme approach p R.P. Duperray, K.V. Protasov, A.Yu. Voronin, Eur. Phys. J. A16 (2003) 27 R.P. Duperray, K.V. Protasov, L. Dérome, M. Buénerd. Eur. Phys. J. A18 (2003) • Direct calculation of the Feynmann diagramme within the microscopic coalescence model without any free parameter. (V.M. Kolybasov & Yu.N. Sokolskikh, Phys.Lett. B225 (1989) 31) M others p or A • This diagramme gives major contribution to the process probability due to mutual cancellation of other contributions (M.A. Braun & V.V. Vechernin, Sov. J. Nucl. Phys. 44 (1986) 506; 36 (1982) 357). • The antinucleons produced in this collision (bloc M) are «slightly virtual» and can fuse without additional interaction with nuclear field

8. Comparaison with experimental data: antideuteron Without any free parameter Good knowledge of the antiproton production spectrum is required

9. Comparaison with expérimental data: antitritium (antihélium) CERN data

10. Propagation • Leaky Box Model / Diffusion Model • Elastic and inelastic (non destructive) scattering of antideuterons are taken into account • Antideutron production in antiproton-ISM collisions is added

11. Secondary antiprotons flux («exercice») Secondary antiproton flux on the Earth level. Solar modulation corresponds to the AMS-01 flight conditions The flux is well described by only secondary antiprotons

12. Secondairy antideuterons flux This work: incertainties due to the coalescence model SUSY predictions Donato et al

13. Secondary antimatter flux

14. Perspectives for AMS (poles for simplicity) • AMS will probably « see » a few secondary antideuterons • Other light secondaires are excluded (the same conclusion as in P.Chardonnet et al) • One detected antinucleus, heavier then antideuteron, will be probably of primary origin

15. Conclusions • Obtained results are based on experimental data and solid phenomenological approaches • flux is by one ordre higher than in previous calculations • Rescattering of ‘s can wash out the SUSY signal • Secondary flux is probably detectable whereas and ones are not