Observation of oscillations and near-barrier suppression in the fusion of $^{20}$O + p

H. Desilets; Rohit Kumar; R. T. deSouza; S. Hudan; C. Ciampi; A. Chbihi; K. W. Brown; Varinderjit Singh; B. Pinheiro; J. L. Ferreira; J. Lubian

arXiv · 2511.01076

Observation of oscillations and near-barrier suppression in the fusion of $^{20}$O + p

H. Desilets·Rohit Kumar·R. T. deSouza·S. Hudan·C. Ciampi·A. Chbihi·K. W. Brown·Varinderjit Singh·B. Pinheiro·J. L. Ferreira·J. Lubian

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Abstract

Using an active target detector, the fusion excitation function for $^{20}$O + $^1$H was measured for the first time. Near the barrier, the fusion cross section manifests an oscillatory behavior with broad peaks $\sim$50-100 keV wide. The presence of these peaks likely reflects the low density of low-angular-momentum states in the quasibound regime. R-matrix coupled channel (CC) calculations that include the first excited 2$^+$ state in $^{20}$O are able to reproduce the observed oscillations. However, one channel CC calculations fail to reproduce the decrease in the sub-barrier cross section experimentally observed.

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H. Desilets, Rohit Kumar, R. T. deSouza, S. Hudan, C. Ciampi, A. Chbihi, K. W. Brown, Varinderjit Singh, B. Pinheiro, J. L. Ferreira, J. Lubian. 2025-11-02. Observation of oscillations and near-barrier suppression in the fusion of $^{20}$O + p. https://arxiv.org/abs/2511.01076

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