Abstract
We compute spectral function for He4 by combining coupled-cluster theory with an expansion of integral transforms into Chebyshev polynomials. Our method allows us to estimate the uncertainty of spectral reconstruction. The properties of the Chebyshev polynomials make the procedure numerically stable and considerably lower in memory usage than the typically employed Lanczos algorithm. We benchmark our predictions with other calculations in the literature and with electron-scattering data in the quasi-elastic peak. The spectral function formalism allows one to extend ab initio lepton-nucleus cross sections into the relativistic regime. This makes it a promising tool for modeling this process at higher-energy transfers. The results we present open the door for studies of heavier nuclei, important for the neutrino oscillation programs.
| Original language | English |
|---|---|
| Article number | 034310 |
| Journal | Physical Review C |
| Volume | 106 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 2022 |
Funding
We appreciate many illuminating discussions with A. Roggero. J.E.S. acknowledges the support of the Humboldt Foundation through a Humboldt Research Fellowship for Postdoctoral Researchers. This work was supported in part by the Deutsche Forschungsgemeinschaft (DFG) through the Cluster of Excellence “Precision Physics, Fundamental Interactions, and Structure of Matter” ( EXC 2118/1) funded by the DFG within the German Excellence Strategy (Project ID 39083149). This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Award Nos. DE-FG02-96ER40963 and DE-SC0018223 (NUCLEI SciDAC-4 collaboration), and Contract No. DE-AC05-00OR22725 with UT-Battelle, LLC (Oak Ridge National Laboratory). Computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program and by the supercomputer Mogon at Johannes Gutenberg Universität Mainz. This research used resources of the Oak Ridge Leadership Computing Facility located at Oak Ridge National Laboratory, which is supported by the Office of Science of the Department of Energy under Contract No. DE-AC05-00OR22725.