Measurement of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Ce</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>140</mml:mn></mml:mrow></mml:mmultiscripts><mml:mo stretchy="false">(</mml:mo><mml:mi mathvariant="normal">n</mml:mi><mml:mo>,</mml:mo><mml:mi>γ</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:math> Cross Section at n_TOF and Its Astrophysical Implications for the Chemical Evolution of the Universe
S. Amaducci, N. Colonna, L. Coséntino, S. Cristallo, P. Finocchiaro, M. Krtic̆ka, C. Massimi, M. Mastromarco, A. Mazzone, E. A. Maugeri, A. Mengoni, Ian U. Roederer, O. Straniero, S. Valenta, D. Vescovi, O. Aberle, V. Alcayne, J. Andrzejewski, L. Audouin, V. Babiano-Suárez, M. Bacak, M. Barbagallo, S. Bennett, E. Berthoumieux, J. Billowes, D. Bosnar, A. Brown, M. Busso, M. Caamaño, L. Caballero, F. Calviño, M. Calviani, D. Cano‐Ott, A. Casanovas, F. Cerutti, E. Chiaveri, G. Cortés, M. A. Cortés‐Giraldo, L. A. Damone, P. J. Davies, Μ. Diakaki, M. Dietz, C. Domingo‐Pardo, R. Dressler, Q. Ducasse, E. Dupont, I. Durán, Z. Eleme, B. Fernández–Domínguez, A. Ferrari, V. Furman, K. Göbel, R. Garg, A. Gawlik-Ramięga, S. Gilardoni, I. F. Gonçalves, E. González-Romero, C. Guerrero, F. Gunsing, Hideo Harada, S. Heinitz, J. Heyse, D. G. Jenkins, A. Junghans, F. Käppeler, Y. Kadi, Akira Kimura, I. Knapová, M. Kokkoris, Y. Kopatch, D. Kurtulgil, I. Ladarescu, C. Lederer-Woods, H. Leeb, J. Lerendegui-Marco, S. J. Lonsdale, D. Macina, A. Manna, T. Martínez, A. Masi, P. Mastinu, E. Mendoza, V. Michalopoulou, P. M. Milazzo, F. Mingrone, J. Moreno-Soto, A. Musumarra, A. Negreţ, R. Nolte, F. Ogállar, A. Oprea, N. Patronis, A. Pavlik, J. Perkowski, C. Petrone, L. Piersanti, E. Pirovano, I. Porras, J. Praena, J. M. Quesada
Abstract
^{140}Ce(n,γ) is a key reaction for slow neutron-capture (s-process) nucleosynthesis due to being a bottleneck in the reaction flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at the n_TOF facility, with an unprecedented combination of a high purity sample and low neutron-sensitivity detectors. The measured Maxwellian averaged cross section is up to 40% higher than previously accepted values. Stellar model calculations indicate a reduction around 20% of the s-process contribution to the Galactic cerium abundance and smaller sizeable differences for most of the heavier elements. No variations are found in the nucleosynthesis from massive stars.