Abstract
Recent investigations suggest that the neutrino-heated hot bubble between the nascent neutron star and the overlying stellar mantle of a type-II supernova may be the site of the r-process. In the preceding α-process building up the elements toA≈100, the4He(2n,γ)6He- and6He(α,n)9Be-reactions bridging the instability gap atA=5 andA=8 could be of relevance. We suggest a mechanism for4He(2n,γ)6He and calculate the reaction rate within the α+n+n approach. The value obtained is about a factor 1.6 smaller than the one obtained recently in the simpler direct-capture model, but is at least three orders of magnitude enhanced compared to the previously adopted value. Our calculation confirms the result of the direct-capture calculation that under representative conditions in the α-process the reaction path proceeding through6He is negligible compared to4He(αn,γ)9Be.
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References
Woosley, S.E., Hofmann, R.D.: Astrophys. J.395, 202 (1992)
Meyer, B.S., Howard, W.M., Mathews, G.J., Woosley, S.E., Hoffmann, R.D.: Astrophys. J.399, 656 (1992)
Howard, W.M., Gloriely, S., Rayet, M., Arnould, M.: Astrophys. J.417, 713 (1993)
Woosely, S.E., Wilson, J.R., Mathews, G.J., Hofmann, R.D., Meyer, B.S.: Astrophys. J.433, 229 (1994)
Witti, J., Janka, H.-Th., Takahashi, K.: Astron. and Astrophys.286, 841 (1994)
Kratz, K.L., Bitouzet, J.-P., Thielemann, F.-K., Möller, P., Pfeiffer, B.: Astrophys. J.403, 216 (1993)
Takahashi, K., Witti, J., Janka, H.-Th.: Astron. and Astrophys.286, 857 (1994)
Fowler, W.A., Caughlan, G.R., Zimmerman, B.: Ann. Rev. Astron. Astrophys.13, 69 (1975)
Görres, J., Herndl, H., Thompson, I.J., Wiescher, M.: Phys. Rev. C52, 2231 (1995) and private communication
Sakuta, S.B., Ogloblin, A.A., Osadchy, O.Ya., Glukhov, Yu.A., Ershov, S.N., Gareev, F.A., Vaagen, J.S.: Europhys. Lett.22, 511 (1993)
Zhukov, M.V., Danilin, B.V., Fedorov, D.V., Bang, J.M., Thompson, I.J., Vaagen, J.S.: Physics Rep.231, 151 (1993)
Balamuth, D.P., Griffioen, K.A., Bush, J.E., Pohl, K.R., Handzy, D.O., Aguirre, A., Sherrill, B.M., Winfield, J.S., Morrissey, D.J., Thoennessen, M.: Phys. Rev. Lett.72, 2355 (1994)
Tanihata, I.: Nucl. Phys. A522, 275c (1991)
Danilin, B.V., Zhukov, M.V., Vaagen, J.S., Bang, J.M.: Phys. Lett. B302, 129 (1993)
Nomoto, K., Thielemann, F.-K., Hiyaji, S.: Astron. and Astrophys.149, 239 (1985)
Görres, J., Wiescher, M., Thielemann, F.-K.: Phys. Rev. C51, 392 (1995)
Rolfs, C., Rodney, W.S.: Cauldrons in the Cosmos. Chicago, University of Chicago Press, 1988
Ajzenberg-Selove, F.: Nucl. Phys. A490, 1 (1988)
Efros V.D., Oberhummer, H.: submitted to Phys. Rev. C, 1995.
Balbes, M.J., Kramer, L.H., Weller, H.R., Tilley, D.R.: Phys. Rev. C43, 343 (1991)
Baz, A.I., Zeldovich, Ya.B., Perelomov, A.M.: Scattering, Reactions and Decay in Non-Relativistic Quantum Mechanics. Nauka, Moscow, 1971
Kobos, A.M., Brown, B.A., Lindsay, R., Satchler, G.R.: Nucl. Phys. A425, 205 (1984)
Oberhummer, H., Staudt, G.: in Oberhummer, H., ed.:Nuclei in the Cosmos. Heidelberg, Springer Verlag, 1991 29–59.
De Vries, H., De Jager, C.W., De Vries, C.: Atom. Data and Nucl. Data Tabl.36, 495 (1987)
Blatt, J.M., Weisskopf, V.F.: Theoretical Nuclear Physics (New York, Wiley, 1962)
Frauenfelder, H., Henley, E.M.: Subatomic Physics. Englewood Cliffs, Prentice-Hall, 1974
Oberhummer, H., Balogh, W., Efros, V.D., Herndl, H., Hofinger, R.: Few-Body Systems Suppl.8, 317 (1995).
Stelson, P.H., Campbell, E.C.: Phys. Rev.106, 1252 (1957)
Anne, R. et al.: Phys. Lett. B250, 19 (1990)
Shimoura, S. et al.: Phys. Lett. B348, 29 (1995)
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Communicated by B. Povh
This work was supported by the Fonds zur Förderung der wissenschaftlichen Forschung in Österreich (project P10361-PHY), by the Österreichische Nationalbank (project 5054) and by the International Science Foundation and Russian Government (grant J4M100).