Relativistic treatment of fermion-antifermion bound states

Leptonic widths of high excitations in heavy quarkonia

“…over the static force F (r) = dV dr . In the nonrelativistic (NR) approximation the relation is [14] …”

Heavy quarkonium effective theory

“…On the other hand, it is straightforward to include one-loop corrections to our result (81), while the EF representations seem to be non-renormalizable objects, and hence any attempt to calculate them in one-loop order should end up with a divergent result [15]. Although the functions ω(n, ℓ) and τ (n, ℓ) are matrix elements of flavour-independent operators, they in fact depend on the flavour through the states.…”

Average kinetic energy of heavy quark and virial theorem

“…With the usual input values [21,22,23] of α s = 0.21 ∼ 0.36, K = 0.19 GeV 2 , m = 0.15 GeV, we obtain µ 2 π = 0.40 ∼ 0.58 GeV 2 for Gaussian trial functions, which is consistent with the result µ 2 π ∼ 0.50 GeV 2 of the QCD sum rule calculations of Ball et al [7]. If we use exponential trial functions, we get higher values of µ 2 π .…”

“…For the study of the bound state properties of hadrons which contain both heavy and light quarks like B-meson, it is appropriate to use the relativistic quark model [12,21], which is a potential model approach with relativistic kinematics.…”