@article{yu_yapa_konig_2024, title={Complex scaling in finite volume}, volume={109}, ISSN={["2469-9993"]}, url={https://doi.org/10.1103/PhysRevC.109.014316}, DOI={10.1103/PhysRevC.109.014316}, abstractNote={Quantum resonances, i.e., metastable states with a finite lifetime, play an important role in nuclear physics and other domains. Describing this phenomenon theoretically is generally a challenging task. In this work, we combine two established techniques to address this challenge. Complex scaling makes it possible to calculate resonances with bound-state-like methods. Finite-volume simulations exploit the fact that the infinite-volume properties of quantum systems are encoded in how discrete energy levels change as one varies the size of the volume. We apply complex scaling to systems in finite periodic boxes and derive the volume dependence of states in this scenario, demonstrating with explicit examples how one can use these relations to infer infinite-volume resonance energies and lifetimes.}, number={1}, journal={PHYSICAL REVIEW C}, author={Yu, Hang and Yapa, Nuwan and Konig, Sebastian}, year={2024}, month={Jan} }
 @article{capel_phillips_andis_bagnarol_behzadmoghaddam_bonaiti_bubna_capitani_duerinck_durant_et al._2023, title={Effective field theory analysis of the Coulomb breakup of the theone-neutron halo nucleus <SUP>19</SUP>C}, volume={59}, ISSN={["1434-601X"]}, DOI={10.1140/epja/s10050-023-01181-7}, abstractNote={AbstractWe analyse the Coulomb breakup of $$^{19}$$
                  
                    
                    19
                  
                C measured at 67A MeV at RIKEN. We use the Coulomb-Corrected Eikonal (CCE) approximation to model the reaction and describe the one-neutron halo nucleus $$^{19}$$
                  
                    
                    19
                  
                C within Halo Effective Field Theory (Halo EFT). At leading order we obtain a fair reproduction of the measured cross section as a function of energy and angle. The description is insensitive to the choice of optical potential, as long as it accurately represents the size of $${}^{18}$$
                  
                    
                    18
                  
                C. It is also insensitive to the interior of the $${}^{19}$$
                  
                    
                    19
                  
                C wave function. Comparison between theory and experiment thus enables us to infer asymptotic properties of the ground state of $$^{19}$$
                  
                    
                    19
                  
                C: these data put constraints on the one-neutron separation energy of this nucleus and, for a given binding energy, can be used to extract an asymptotic normalisation coefficient (ANC). These results are confirmed by CCE calculations employing next-to-leading order Halo EFT descriptions of $${}^{19}$$
                  
                    
                    19
                  
                C: at this order the results for the Coulomb breakup cross section are completely insensitive to the choice of the regulator. Accordingly, this reaction can be used to constrain the one-neutron separation energy and ANC of $${}^{19}$$
                  
                    
                    19
                  
                C.}, number={11}, journal={EUROPEAN PHYSICAL JOURNAL A}, author={Capel, Pierre and Phillips, Daniel R. and Andis, Andrew and Bagnarol, Mirko and Behzadmoghaddam, Behnaz and Bonaiti, Francesca and Bubna, Rishabh and Capitani, Ylenia and Duerinck, Pierre-Yves and Durant, Victoria and et al.}, year={2023}, month={Nov} }
 @article{yapa_konig_2022, title={Volume extrapolation via eigenvector continuation}, volume={106}, ISSN={["2469-9993"]}, url={https://doi.org/10.1103/PhysRevC.106.014309}, DOI={10.1103/PhysRevC.106.014309}, abstractNote={We develop an extension of eigenvector continuation (EC) that makes it possible to extrapolate simulations of quantum systems in finite periodic boxes across large ranges of box sizes. The formal justification for this approach, which we call finite-volume eigenvector continuation (FVEC), is provided by matching periodic functions at different box sizes. As concrete FVEC implementation we use a discrete variable representation based on plane-wave states and present several applications calculated within this framework.}, number={1}, journal={PHYSICAL REVIEW C}, author={Yapa, Nuwan and Konig, Sebastian}, year={2022}, month={Jul} }