Download presentation

Presentation is loading. Please wait.

Published byAbel Lime Modified over 2 years ago

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 40-80 MeV/nucleon GANIL - 1, 2 250 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 03 @ 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 exp.) @ 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) 011602

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

Similar presentations

OK

E1 Strength distribution of halo nuclei observed via the Coulomb breakup Takashi Nakamura Tokyo Institute of Technology Workshop on Statistical Nuclear.

E1 Strength distribution of halo nuclei observed via the Coulomb breakup Takashi Nakamura Tokyo Institute of Technology Workshop on Statistical Nuclear.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google