2020/09/30 by Marc Illa, Silas R. Beane, Emmanuel Chang +11 · 39 citations
Physics and Astronomy · #Baryon #Excited state #High-Energy Particle Collisions Research #Lattice QCD #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #Quark #Scattering #Singlet state #hep-lat #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.103.054508
published in Physical review. D/Physical review. D. 103(5) (American Physical Society) · 69 pages, 31 figures and 25 tables; published version
openalex created_date 2020/10/01 · openalex publication_date 2021/03/19 · arxiv created 2021/03/23 · arxiv updated 2021/03/24 · openalex updated_date 2026/08/06
The interactions between two octet baryons are studied at low energies using lattice quantum chromodynamics (LQCD) with larger-than-physical quark masses corresponding to a pion mass of m_\ensuremathπ\ensuremath∼450 MeV and a kaon mass of mK\ensuremath∼596 MeV. The two-baryon systems that are analyzed range from strangeness S=0 to S=\ensuremath-4 and include the spin-singlet and triplet NN, \mathrm\ensuremathΣN (I=3/2), and \mathrm\ensuremathΞ\mathrm\ensuremathΞ states, the spin-singlet \mathrm\ensuremathΣ\mathrm\ensuremathΣ (I=2) and \mathrm\ensuremathΞ\mathrm\ensuremathΣ (I=3/2) states, and the spin-triplet \mathrm\ensuremathΞN (I=0) state. The corresponding s-wave scattering phase shifts, low-energy scattering parameters, and binding energies when applicable are extracted using L"uscher's formalism. While the results are consistent with most of the systems being bound at this pion mass, the interactions in the spin-triplet \mathrm\ensuremathΣN and \mathrm\ensuremathΞ\mathrm\ensuremathΞ channels are found to be repulsive and do not support bound states. Using results from previous studies of these systems at a larger pion mass, an extrapolation of the binding energies to the physical point is performed and is compared with available experimental values and phenomenological predictions. The low-energy coefficients in pionless effective field theory (EFT) relevant for two-baryon interactions, including those responsible for SU(3) flavor-symmetry breaking, are constrained. The SU(3) flavor symmetry is observed to hold approximately at the chosen values of the quark masses, as well as the SU(6) spin-flavor symmetry, predicted at large Nc. A remnant of an accidental SU(16) symmetry found previously at a larger pion mass is further observed. The SU(6)-symmetric EFT constrained by these LQCD calculations is used to make predictions for two-baryon systems for which the low-energy scattering parameters could not be determined with LQCD directly in this study, and to constrain the coefficients of all leading SU(3) flavor-symmetric interactions, demonstrating the predictive power of two-baryon EFTs matched to LQCD.