1 / 14

1 TU Darmstadt, Germany — 2 Osaka University, Japan — 3 iThemba LABS, South Africa —

TU DARMSTADT. S-DALINAC. Neutrino Nucleosynthesis of Exotic, Odd-Odd Nuclei 138 La and 180 Ta. Peter von Neumann-Cosel Institut für Kernphysik, Technische Universität Darmstadt. A. Byelikov 1 , T. Adachi 2 , H. Fujita 3 , Y. Fujita 2 , A. Heger 4 , Y. Kalmykov 1 , K. Langanke 5 ,

adamma
Download Presentation

1 TU Darmstadt, Germany — 2 Osaka University, Japan — 3 iThemba LABS, South Africa —

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. TU DARMSTADT S-DALINAC Neutrino Nucleosynthesis of Exotic, Odd-Odd Nuclei 138La and 180Ta Peter von Neumann-Cosel Institut für Kernphysik, Technische Universität Darmstadt A. Byelikov1, T. Adachi2, H. Fujita3, Y. Fujita2, A. Heger4, Y. Kalmykov1, K. Langanke5, G. Martínez-Pinedo5, PvNC1, R. Neveling3, A. Richter1, A. Shevchenko1, Y. Shimbara2, F.D. Smit3, A. Tamii6, S.E. Woosley7 and M. Yosoi6 1TU Darmstadt, Germany — 2Osaka University, Japan — 3iThemba LABS, South Africa — 4LANL, USA, 5GSI Darmstadt, Germany — 6RCNP Osaka, Japan — 7UC Santa Cruz, USA

  2. Outline • Motivation • Neutrino nuclesynthesis of 138La and 180Ta • High resolution measurement of GT strength • Astrophysical implications

  3. Exotic Nuclides

  4. Nucleosynthesis of 138La s-process r-process p-process

  5. Production through Neutrino Processes • Neutral current reactions: 139La(n,n′n)138La • 181Ta(n,n′n)180Ta • Charged current reactions: 138Ba(ne,e-)138La • 180Hf(ne,e-)180Ta • Complete stellar evolution in massive stars with • improved RPA calculations for n-nucleus reactions A. Heger et al., Phys. Lett. B 606 (2005) 258

  6. Different Production Processes of 138La • 138La: pure n process production by cc reactions • 180Ta: 50% n process, 50% p process

  7. Theoretical Prediction • Low neutrino energies small q DL = 0 GT strength • RPA predicts main GT resonance well above neutron threshold • Predictions for the low-lying strength are questionable

  8. Experimental Requirements • (ne,e) Gamow-Teller strength (p,n) or (3He,t) • Gamow-Teller part narrow angle cut around 0° • Intermediate energies (100 – 400 MeV/u) • simple one-step reaction mechanism • spin – isospin response enhanced (3He,t) reaction at RCNP

  9. 138La Spectrum RCNP • Target: 138BaCO4 embedded in polyvinylalcohol

  10. GT Strength Distribution in 138La

  11. Cumulative Strength in 138La • B(GT–)exp» 117% B(GT–)theo at 7.47 MeV

  12. Cumulative Strength in 180Ta • B(GT–)exp» 276% B(GT–)theo at 6.64 MeV

  13. Yields of 138La and 180Ta for a 15 M Star 138La yield 180Ta yield g-process 4 8 neut. curr. ch. curr. 4 MeV 3 6 ch. curr. 8 MeV 2 4 solar 1 2 solar • Branching ratio to 180Ta isomer about 35%

  14. Conclusions • GT strength in 138La and 180Ta below • particle threshold extracted • 138La is essentially produced in the n process • 180Ta at least partially produced in the n process • Full results: • A. Byelikov et al., PRL 98, 082501 (2007)

More Related