Observation of double pygmy resonances in ^195,196Pt and enhanced astrophysical reaction rates

2014/02/11 by F. Giacoppo, Giacoppo, F., F. L. Bello Garrote +27
Physics and Astronomy · #FOS: Physical sciences #Nuclear Experiment (nucl-ex) #Nuclear Physics and Applications #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.1402.2451

openalex publication_date 2014/02/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

Our measurements of ^195,196Pt γ-strength functions show a double-humped enhancement in the E_γ= 4-8 MeV region. For the first time, the detailed shape of these resonances is revealed for excitation energies in the quasicontinuum. We demonstrate that the corresponding neutron-capture cross sections and astrophysical reaction rates are increased by up to a factor of 2 when these newly observed pygmy resonances are included. These results lend credence to theoretical predictions of enhanced reaction rates due to such pygmy resonances and hence are important for a better understanding of r-process nucleosynthesis.

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