Eur. Phys. J. A (2021) 57: 272
https://doi.org/10.1140/epja/s10050-021-00584-8

Regular Article - Experimental Physics

Resolution of a long-standing discrepancy in the ${}^{17}$O${+}^{12}$C fusion excitation function

¹ Department of Physics, Florida State University, Tallahassee, 32306, Florida, USA
² National Centre for Nuclear Research, ul. Andrzeja Sołtana 7, 05-400, Otwock, Poland

^a bwa15@my.fsu.edu

Received: 27 May 2021
Accepted: 27 August 2021
Published online: 13 September 2021

Abstract

There has been a long-standing discrepancy between existing measurements of the total fusion cross section for the ${}^{17}$O ${+}^{12}$C system at $E_{\mathrm{c}.\mathrm{m}.}\sim 14$ MeV. In order to resolve this inconsistency, the cross section was measured in two overlapping energy ranges using an ${}^{17}$O beam and the Encore active target detector at Florida State University. Encore is a self-normalizing detector that measures a large portion of the fusion excitation function with a single beam energy. It also provides full angular coverage of the measured evaporation residues, thus ensuring a model independent measurement of the total fusion cross section. The data reported here show an oscillatory structure not previously observed in this system and agree with all previously reported measurements, resolving the long-standing discrepancy. Coupled reaction channels calculations reproduce the data except in the region of the the oscillation, which matches a similar structure seen in the ${}^{16}$O ${+}^{12}$C total fusion excitation function.