2003/11/30 by А. М. Бадалян, A. M. Badalian, A. I. Veselov +2 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1103/physrevd.70.016007
17 pages, no figures, 6 tables
arxiv created 2004/04/09 · openalex publication_date 2004/07/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The bb spectrum is calculated with the use of a relativistic Hamiltonian where the gluon-exchange potential between a quark and an antiquark is taken as in background perturbation theory. We observed that the splittings \ensuremathΔ1=\ensuremathΥ(1D)\ensuremath-\ensuremathχb(1P) and other splittings between low-lying states are very sensitive to the QCD constant \ensuremathΛV(nf) which occurs in the vector scheme, and good agreement with the experimental data is obtained for \ensuremathΛV(2\ensuremath-loop, nf=5)=325\ifmmode±\else\textpm\fi10MeV which corresponds to the conventional \ensuremathΛ_MS(2\ensuremath-loop,nf=5)=238\ifmmode±\else\textpm\fi7MeV, \ensuremathαs(2\ensuremath-loop, MZ)=0.1189\ifmmode±\else\textpm\fi0.0005, and to a large freezing value of the background coupling: \ensuremathαcrit(2\ensuremath-loop, q2=0)=\ensuremathαcrit(2\ensuremath-loop, \stackrel\ensuremath→r\ensuremath∞)=0.58\ifmmode±\else\textpm\fi0.02. If the asymptotic freedom behavior of the coupling is neglected and an effective freezing coupling \ensuremathαstatic=const is introduced, as in the Cornell potential, then precise agreement with \ensuremathΔ1(exp) and \ensuremathΔ2(exp) can be reached for the rather large Coulomb constant \ensuremathαstatic=0.43\ifmmode±\else\textpm\fi0.02. We predict a value for the mass M(2D)=10451\ifmmode±\else\textpm\fi2MeV.