Strong three-meson couplings ofJ/ψandηc

Abstract

We discuss the strong couplings gP P V and gV V P for vector (V ) and pseudoscalar (P ) mesons, at least one of which is a charmonium state J/ψ or ηc. The strong couplings are obtained as residues at the poles of suitable form factors, calculated in a broad range of momentum transfers using a dispersion formulation of the relativistic constituent quark model. The form factors obtained in this approach satisfy all constraints known for these quantities in the heavy-quark limit. Our results suggest sizably higher values for the strong meson couplings than those reported in the literature from QCD sum rules.

Strong Couplings of Three Mesons with Charm(ing) Involvement

“…Confronting, in Table 4, our D (s) -D ( * ) (s) -J/ψ predictions with QCD sum-rule outcomes [18][19][20], the QCD sum-rule estimates prove to be lower than ours [15][16][17] by a factor of two. Table 3.…”

“…3(a)) [15][16][17] and g DD * η c from F Fig. 3(b)) [15][16][17]; for further examples of such multiple involvements, consult Tables III, V, and VI of Ref. [15].…”

“…Table 3. Charm(ing) three-meson strong couplings: quark-model-based dispersion-approach outcomes [15][16][17]. …”

Heavy-Meson Decay Constants: Isospin Breaking from QCD Sum Rules

“…Our actual aim [23,24] is the impact of the isospin-spoiling disparity of the u-and d-quark masses [25] m u (2 GeV) = 2.3 …”

“…As a consequence of these studies, we proposed a somewhat modified algorithm that provides estimates of intrinsic errors [7][8][9][10][11]. With this improvement at our disposal, we revisited QCD sum-rule extractions of a variety of hadronic observables, particularly of the leptonic decay constants of the heavy-light mesons [12][13][14][15][16], which led us to the conclusion [17][18][19][20][21] that, in the bottom-meson system, the decay constants of the pseudoscalar mesons exceed those of their vector counterparts, as has been confirmed thereafter in lattice QCD [22].For pseudoscalar (P q ) and vector (V q ) mesons H q ≡ P q , V q , of mass M H q , built up by a heavy quark Q = c, b and a light quark q = u, d of masses m Q and m q , respectively, the decay constants, f H q , of these mesons [with momentum p and, in the case of vector mesons, polarization vector ε µ (p)] are defined, in terms of suitable, interpolating heavy-light axial-vector (A) and vector (V) quark-current operators, byOur actual aim [23,24] …”