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The 40Ca(alpha,gamma)44Ti reaction in the energy regime of supernova nucleosynthesis

H. Nassar·M. Paul·I. Ahmad·Y. Ben-Dov·J. Caggiano·S. Ghelberg·S. Goriely·J. P. Greene·M. Hass·A. Heger·A. Heinz·D. J. Henderson·R. V. F. Janssens·C. L. Jiang·Y. Kashiv·B. S. Nara Singh·A. Ofan·R. C. Pardo·T. Pennington·K. E. Rehm·G. Savard·R. Scott·R. Vondrasek
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Abstract

The 44Ti(t1/2 = 59 y) nuclide, an important signature of supernova nucleosynthesis, has recently been observed as live radioactivity by gamma-ray astronomy from the Cas A remnant. We investigate in the laboratory the major 44Ti production reaction, 40Ca(alpha,gamma)44Ti (E_cm = 0.6-1.2 MeV/u), by direct off- line counting of 44Ti nuclei. The yield, significantly higher than inferred from previous experiments, is analyzed in terms of a statistical model using microscopic nuclear inputs. The associated stellar rate has important astrophysical consequences, increasing the calculated supernova 44Ti yield by a factor ~2 over previous estimates and bringing it closer to Cas A observations.

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H. Nassar, M. Paul, I. Ahmad, Y. Ben-Dov, J. Caggiano, S. Ghelberg, S. Goriely, J. P. Greene, M. Hass, A. Heger, A. Heinz, D. J. Henderson, R. V. F. Janssens, C. L. Jiang, Y. Kashiv, B. S. Nara Singh, A. Ofan, R. C. Pardo, T. Pennington, K. E. Rehm, G. Savard, R. Scott, R. Vondrasek. 2006-01-11. The 40Ca(alpha,gamma)44Ti reaction in the energy regime of supernova nucleosynthesis. https://doi.org/10.1103/physrevlett.96.041102

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