# Nuclear Physics in Astrophysics - X

Sep 4 – 9, 2022
CERN
Europe/Zurich timezone

## Sheding light on $^{17}$O(n,$\alpha$)$^{14}$C reaction at astrophysical energies with Trojan Horse Method and Asymptotic Normalization Coefficient

Sep 6, 2022, 6:00 PM
3h
61/1-201 - Pas perdus - Not a meeting room - (CERN)

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Poster

### Speaker

Giovanni Luca Guardo

### Description

The $^{17}$O(n,$\alpha$)$^{14}$C reaction is considered in astrophysical codes for its role in the astrophysically relevant "s(slow)-process" since it could act as a possible “neutron-poison” for the neutron induced nucleosynthesis thus influencing the final stellar abundances of some elements such as Fe, Ni or Sr. Thus, its reaction rate must be known in the energy region of interest for astrophysics, going from few keV’s up to about 400 keV. At such energies, the intermediate $^{17}$O+n$\rightarrow^{18}$O nucleus presents four excited levels (8038, 8125, 8213, and 8282 keV’s) affecting the magnitude of the $^{17}$O+n cross section at astrophysical energies because of the neutron emission threshold at 8044 keV for $^{18}$O. Although the role of the two 8213 keV (J$^{\pi}$=2$^{+}$) and 8282 keV (J$^{\pi}$=3$^{-}$) was already investigated in the direct measurements, insufficient informations are up to now available about the 8125 keV (J$^{\pi}$=5$^{-}$) resonant level, thus requiring a detailed experiment.

Indirect methods have been largely proved in the past as a complementary way of accreting our knowledge about nuclear structure and low-energy cross section measurements. Among these, the neutron induced reaction cross section appear to be of particular interest since their role both for unstable and stable beams. In view of this, we report here the combined study of the $^{17}$O(n,$\alpha$)$^{14}$C accomplished by the Trojan Horse Method (THM) and the Asymptotic Normalization Coefficient (ANC) method. The low lying resonances 8038, 8125, 8213, and 8282 keV in $^{18}$O are studied and $\Gamma_n$ are derived. A comparison with recent data and recent THM experimental data is presented. The independent ANC investigation corroborate our previous THM results, confirms the consistence of the two indirect investigation and shows new frontiers also in view of neutron induced reactions with radioactive ion beams.

### Co-authors

Livio Lamia (Università di Catania) Juan Pablo Fernandez Garcia (Universidad de Sevilla (ES)) Marco La Cognata (Universita e INFN, Catania (IT)) Giuseppe D'Agata (Università degli Studi di Catania - Dipartimento di Fisica e Astronomia "Ettore Majorana" & Laboratori Nazionali del Sud - INFN) sara palmerini (Università degli Studi di Perugia - INFN sez. Perugia) Diego Vescovi (GSSI e INFN Perugia (IT)) Vaclac Burjan (Nuclear Physics Institute of the Czech Academy of Sciences) Vaclav Kroha (Nuclear Physics Institute of the Czech Academy of Sciences) Jaromir Mrazek (Nuclear Physics Institute of the Czech Academy of Sciences) Alessandro Alberto Oliva (INFN-LNS & University of Catania) Rosario Gianluca Pizzone (INFN LNS) Giuseppe Gabriele Rapisarda (INFN-LNS & University of Catania) Prof. Stefano Romano (INFN-LNS & University of Catania) Maria Letizia Sergi (INFN-LNS & University of Catania) Roberta Sparta (Universita e INFN, Catania (IT)) Aurora Tumino (Facoltà di Ingegneria ed Architettura, Kore University and INFN - Laboratori Nazionali del Sud)