Presentation is loading. Please wait.

Presentation is loading. Please wait.

Nara, June 03 Solar neutrino production rates by heavy ion reactions T. Motobayashi (RIKEN) 7 Be(p,  ) 8 B reaction pp chain in the sun direct measurement.

Similar presentations


Presentation on theme: "Nara, June 03 Solar neutrino production rates by heavy ion reactions T. Motobayashi (RIKEN) 7 Be(p,  ) 8 B reaction pp chain in the sun direct measurement."— Presentation transcript:

1 Nara, June 03 Solar neutrino production rates by heavy ion reactions T. Motobayashi (RIKEN) 7 Be(p,  ) 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 RIKEN - 1, 2, MSU MeV/nucleon GANIL - 1, MeV/nucleon Summary / discussions

2 Nara, June 03

3 1990

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

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

6 Nara, June 03 E rel <= p p, p 7Be,  p-Be  E rel : Independent of  E in  E rel =200 keV p+X, T 0 =100 AMeV, E rel =1 MeV,  =0.5 deg.  v=1%

7 Nara, June RIKEN ~50 MeV/nucleon

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

9 Nara, June 03 Questions Nuclear contribution (E1)  small but l=2 ? Higher order effects Different multipolarities 7 Be(p,  ) 8 B E1 + M1 (4-15 %) + E2 (  1%) 208 Pb( 8 B,p 7 Be) 208 PbE1 + E2 (4-15 %) + M1(  1%) angular (  8 ) distribution angular correlation

10 Nara, June 03

11 RIKEN-2 small E2 (l=2)

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

13 Nara, June 03 E rel (MeV) d  /dE (mb/MeV)

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

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

16 Nara, June 03 S 17 (eV b) Coulomb dissociationrecent direct capture (+ GSI-2)

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

18 Nara, June 03 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

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

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

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

22 Nara, June 03 S 17 at E=0 RIKEN-1 RIKEN-2 GSI-1 GSI-2 MSU Beijing TAMU-1 TAMU-2 Ogata et al. (2003)

23 Nara, June 03 Summary Indirect determination of S 17 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 RI-beam theory experiment


Download ppt "Nara, June 03 Solar neutrino production rates by heavy ion reactions T. Motobayashi (RIKEN) 7 Be(p,  ) 8 B reaction pp chain in the sun direct measurement."

Similar presentations


Ads by Google