Related papers: Quarkonium Spectroscopy and Perturbative QCD: A Ne…
Non-relativistic bound state theories for QED and QCD have become fairly mature and amenable to a textbook-level understanding and computation. In this talk we give an introductory review of the following subjects related to the recent…
An effective hamiltonian for heavy quarkonia is derived from QCD by separating gluonic fields in background and quantum fields and neglecting anharmonic contributions. Mesonic states with nonperturbative gluonic components are constructed.…
We estimate the QCD coupling constant from a lattice calculation of the bottomonium spectrum. The second order perturbative expansion of the plaquette expectation value is employed to determine alpha_S at a scale set by the 2S-1S and 1P-1S…
We present results of simulations of the quenched quarkonium spectrum at two values of the lattice spacing and for quark masses around $m_c$ using the tadpole improved clover action. Attention is focussed on the lowest lying S and P states,…
Recent lattice quantum chromodynamics (lQCD) computations of bottomonium correlation functions with extended sources provide new insights into heavy-quark dynamics at distance scales which are of the order of the inverse temperature. We…
The interaction of quarkonium with nuclei is studied in the $m_Q\rightarrow \infty$ limit of QCD, where the binding energy is found to be exactly computable. The dominant contribution to the interaction is from two-gluon operators. The…
The bottomonium spectrum is computed in dynamical 2+1 flavor lattice QCD, using NRQCD for the b quarks. The main calculations in this work are based on gauge field ensembles generated by the RBC and UKQCD collaborations with the Iwasaki…
We consider the properties of the ground state of bottomium. The $\Upsilon$ mass is evaluated to two loops, and including leading higher order [$O(\alpha_s^5\log\alpha_s)$] and $m_c^2/m_b^2$ corrections. This allows us to present updated…
We study how the isospin asymmetry affects quarkonium states in QCD at near zero temperature. Using lattice Non-Relativistic QCD formalism, we calculate bottom quark correlators in the gauge field ensembles generated with $N_f = 2 + 1$…
We review our estimations on the light scalar $\bar{q}q$, $(\bar{q}q')(\bar{q'}q)$ and $\overline{qq'}qq'$ ($q,q'\equiv u,d,s$) states from relativistic Laplace sum rule (LSR) within stability criteria and including higher order…
In this work, we explore the ground state mass spectrum of the bottom-charm baryon states in the framework of the QCD sum rules in a comprehensive way. In calculations, we distinguish the contributions of the positive-parity and…
We investigate the effects of including the full three-loop QCD correction to the static short distance $1/r$ potential on the spectroscopy and decays in the charmonium and upsilon systems. We use a variational technique with the full…
The mass spectrum of $b\bar{b}$ states has been obtained using the phenomenological relativistic quark model (RQM). The Hamiltonian used in the investigation has confinement potential and confined one gluon exchange potential (COGEP). In…
The spectra and decay rates of $c \bar c$ and $b \bar b$ levels are well described, for the most part, by a power-law potential of the form $V(r)=\lambda(r^{\alpha}-1)/\alpha+{\rm const.}$, where $\alpha\simeq 0$. The results of an…
We show the results of a quark model calculation of the bottomonium spectrum with self energy corrections due to the coupling to the meson-meson continuum. The bare masses used in the calculation are computed within the relativized quark…
We present results on the bottomonium spectrum at temperatures above and below the deconfinement crossover temperature, $T_c$, from dynamical lattice QCD simulations. The heavy quark is treated with a non-relativistic effective field theory…
We examine the total energy E_tot(r) = 2 m_pole + V_QCD(r) of the b\bar b system within perturbative QCD up to O(\alpha_S^3). We extend a previous analysis by incorporating effects of the non-zero charm-quark mass in loops. We find that,…
The spectrum of the negative-parity spin-1/2 $\Lambda$ baryons is studied using lattice QCD and hadronic effective theory in a unitarized coupled-channel framework. A direct comparison between the two approaches is possible by considering…
Radiative QCD corrections significantly influence the theoretical predictions for the decay rates of the $Z$ and the Higgs boson. The status of the QCD calculations to the hadronic $Z$ width is reviewed. The role of mass corrections from…
The dominant contribution of the next-to-leading order perturbative QCD corrections to the Upsilon -> X gamma photon energy spectrum for photon energies w ~ m_b alpha_s can be obtained trivially from the knowledge of the corresponding…