2020/09/24 by M. C. Gordillo, F. De Soto, Jorge Segovia +1 · 1 citation
Physics and Astronomy · #Atomic physics #Bar (unit) #Ground state #High-Energy Particle Collisions Research #Hyperfine structure #Invariant mass #Meson #Monte Carlo method #Nuclear physics #Observable #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Quark #Tetraquark #hep-ex #hep-lat #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1103/physrevd.102.114007
19 pages, 7 figures, 15 tables
arxiv created 2020/09/24 · openalex publication_date 2020/12/03 · arxiv updated 2020/12/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We use a diffusion Monte Carlo method to solve the many-body Schr"odinger equation describing fully heavy tetraquark systems. This approach allows us to reduce the uncertainty of the numerical calculation at the percent level, accounts for multiparticle correlations in the physical observables, and avoids the usual quark clustering assumed in other theoretical techniques applied to the same problem. The interaction between particles was modeled by the most general and accepted potential---i.e., a pairwise interaction including Coulomb, linear-confining and hyperfine spin-spin terms. This means that, in principle, our analysis should provide some rigorous statements about the mass location of the all-heavy tetraquark ground states, which is particularly timely due to the very recent observation made by the LHCb Collaboration of some enhancements in the invariant mass spectra of J/\ensuremathψ pairs. Our main results are as follows: (i) The cccc, ccbb (bbcc), and bbbb lowest-lying states are located well above their corresponding meson-meson thresholds. (ii) The JPC=0++ cccc ground state with preferred quark-antiquark pair configurations is compatible with the enhancement(s) observed by the LHCb Collaboration. (iii) Our results for the cccb and bbcb sectors seem to indicate that the 0+ and 1+ ground states are almost degenerate, with the 2+ located around 100 MeV above them. (iv) Smaller mass splittings for the cbcb system are predicted, with absolute mass values in reasonable agreement with other theoretical works. (v) The 1++ cbcb tetraquark ground state lies at its lowest S-wave meson-meson threshold, and it is compatible with a molecular configuration.