New results on inclusive quarkonium decays

I review some recent progress, leading to a substantial reduction in the number of non-perturbative parameters, in the calculation of inclusive quarkonium decay widths in the framework of non-relativistic effective field theories.Comment: 4 pages, 3 figures, to be published in the proceedings of the XXXVIIth Rencontres de Moriond (QCD and High Energy Hadronic Interactions), 16-23 March 2002, Les Arcs, Franc

The BcB_c mass up to order αs4\alpha_s^4

We evaluate in perturbative QCD, up to order $\alpha_s^4$, the mass of the $B_c$. We use the so-called 1S-mass in order to improve the convergence of the perturbative series. Our result is $E(B_c)_{pert} = 6326^{+29}_{-9}$ MeV. Non-perturbative effects are discussed. A comparison with potential models seems to be consistent with non-perturbative contributions of the order $- (40\div 100)$ MeV.Comment: 14 pages, revtex, 2 figures, minor changes, discussion on the non-perturbative corrections added, final version to appear in Phys. Rev.

Non-perturbative Dynamics of the Heavy-Light Quark System

We obtain the non-perturbative interaction kernel of the heavy-light quark system in a gauge-invariant approach. The potential and the sum rules limit are discussed. Some insight is given in the light quark interaction.Comment: 4 pages, latex (aipproc.sty), 1 figure included, to be published in the Proceedings of Hadron97 (BNL, 25-30 August 1997), Ed. S. U. Chung, AI

The 1P quarkonium fine splittings at NLO

We calculate the 1P heavy quarkonium fine splittings at NLO and discuss the impact of the calculation on the chi_b(1P) splittings.Comment: 10 pages, 3 figure

Precise determination of the eta_c mass and width in the radiative J/Psi -> eta_c gamma decay

We present an effective field theory based extraction of the eta_c mass and width from a recent measurement by CLEO of the photon line shape in J/Psi -> eta_c gamma decay.Comment: 3 pages, 3 figures, contribution to 'Quark Confinement and the Hadron Spectrum IX', Univ. Complutense de Madrid, August 30th-September 3rd, 201

Electromagnetic quarkonium decays at order v^7

We compute S-wave and P-wave electromagnetic quarkonium decays at order v^7 in the heavy-quark velocity expansion. In the S-wave case, our calculation confirms and completes previous findings. In the P-wave case, our results are in disagreement with previous ones; in particular, we find that two matrix elements less are needed. The cancellation of infrared singularities in the matching procedure is discussed.Comment: Eq. (A.1) and following comment corrected, rest of the paper unchange

Symmetries of the Three Heavy-Quark System and the Color-Singlet Static Energy at NNLL

We study the symmetries of the three heavy-quark system under exchange of the quark fields within the effective field theory framework of potential non-relativistic QCD. The symmetries constrain the form of the matching coefficients in the effective theory. We then focus on the color-singlet sector and determine the so far unknown leading ultrasoft contribution to the static potential, which is of order alpha_s^4 ln(\mu), and consequently to the static energy, which is of order alpha_s^4 ln(alpha_s). Finally, in the case of an equilateral geometry, we solve the renormalization group equations and resum the leading ultrasoft logarithms for the static potential of three quarks in a color singlet, octet and decuplet representation.Comment: 27 pages, 3 figures; matches journal versio