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Solar neutrino production rates by heavy ion reactions

Solar neutrino production rates by heavy ion reactions. 7 Be(p, g ) 8 B reaction pp chain in the sun direct measurement of S 17 c.f. Snover Indirect methods Coulomb dissociation ”ANC” method 8 B Coulomb dissociation experiments

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Solar neutrino production rates by heavy ion reactions

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  1. Solar neutrino production rates by heavy ion reactions 7Be(p,g)8B reaction pp chain in the sun direct measurement of S17 c.f. Snover Indirect methods Coulomb dissociation ”ANC” method 8B Coulomb dissociation experiments RIKEN - 1, 2, MSU 40-80 MeV/nucleon GANIL - 1, 2250 MeV/nucleon Summary / discussions T. Motobayashi (RIKEN) Nara, June 03

  2. Nara, June 03

  3. 1990 Nara, June 03

  4. Coulomb dissociation 8B+208Pb -> 7Be+p+208Pb (C.D.) virtual photon theory or DWBA 8B(g,p)7Be (abs.) detailed balance 7Be(p,g)8B (capt.) large s thick target (intermediate energy) experiments with R.I. beams Nara, June 03

  5. detailed balance virtual photon number (intermediate energy) thick target charged particle detection indirect i.e.nucl. force / higher order / E2 Nara, June 03

  6. Erel <= pp, p7Be, qp-Be DErel : Independent of DEin p+X, T0=100 AMeV, Erel=1 MeV, Dq=0.5 deg.Dv=1% DErel=200 keV Nara, June 03

  7. @ RIKEN ~50 MeV/nucleon Nara, June 03

  8. RIKEN-2 (98) RIKEN-I (94) Nara, June 03

  9. Questions Nuclear contribution (E1)small but l=2 ? Higher order effects Different multipolarities 7Be(p,g)8B E1 + M1 (4-15 %) + E2 (~0.1%) 208Pb(8B,p 7Be)208Pb E1 + E2 (4-15 %) + M1(~0.1%) angular (q8) distribution angular correlation Nara, June 03

  10. Nara, June 03

  11. RIKEN-2 small E2 (l=2) Nara, June 03

  12. @ GSI 254 MeeV/nucleon microstrip 2 x PPAC (2nd exp.) Nara, June 03

  13. ds/dE (mb/MeV) Erel (MeV) Nara, June 03

  14. transverse momentum distributions consistent with small E2 contribution Nara, June 03

  15. azimuthal- / polar-angle distributions Nara, June 03

  16. S17 (eV b) Coulomb dissociation recent direct capture (+ GSI-2) Nara, June 03

  17. parallel momentum distribution (MSU) Davids et al., Phys. Rev. Lett. 81 (1998) 2209 Nara, June 03

  18. possible corrections • Multipolarities • E1 dominance: OK in 90% for Coul. Diss. • E2 : controversy ? • angular distribution (RIKEN) small • P// distribution (MSU) 10-15% • Angular correlation (GSI) small • M1: only at the resonance • Nuclear contribution • ~1% (E1) <- microscopic calc. • large ? (E2) <- collective form factor • --> calc.w. microscopic f.f. / CDCC / exp. • Higher order effects • Post Coulomb acceleration: small • multistep excitation: E1-E2 interference • --> dynamical calc. / CDCC Nara, June 03

  19. l = 1 l = 2 C > N C ~N Nara, June 03

  20. Asymptotic Normalization Coefficient (ANC) Method 7Be(p,g)8B 7Be(d,n)8B tail amplitude of w.f.: weak potential parameter dependence Nara, June 03

  21. Analysis: Ogata, Yahiro, Iseri, Kamimura Phys. Rev. C 67 (2003) 011602 Nara, June 03

  22. S17 at E=0 Beijing Ogata et al. (2003) GSI-1 GSI-2 RIKEN-2 RIKEN-1 MSU TAMU-2 TAMU-1 Nara, June 03

  23. Indirect determination of S17 Coulomb dissociation ANC in 10-15% agreement with direct-capture results For better accuracy control of reaction mechanism nuclear force higher-order process E2-related corrections Summary RI-beam theory experiment Nara, June 03

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