Related papers: Static QCD potential at three-loop order
We review a new technique for the calculation of two-loop amplitudes and discuss as an example the fermionic contributions to e+ e- --> q qbar g.
Using SU(3) lattice QCD, we perform the detailed studies of the three-quark and the multi-quark potentials. From the accurate calculation for more than 300 different patterns of 3Q systems, the static ground-state 3Q potential $V_{\rm…
Within an effective field theory framework, we obtain an expression, with O(1/m^2) accuracy, for the energies of the gluonic excitations between heavy quarks, which holds beyond perturbation theory. For the singlet heavy quark--antiquark…
A non-perturbative calculation of the effective thermal potential between heavy $Q$ and $\bar Q$ from lattice QCD is difficult, and usually involves a Bayesian analysis. Here we present a simple method to obtain the potential from smeared…
We present the even-N moments N =< 20 of the fourth-order (N^3LO) contribution P_{gq}^(3)(x) to the quark-to-gluon splitting function in perturbative QCD. These moments, obtained by analytically computing off-shell operator matrix elements…
We discuss the thermodynamics of gluons in the background of static quark sources. In order to do so we formulate the quenched limit of QCD at non-zero baryon number. A first numerical analysis of this system shows that it undergoes a…
We compute the three-loop QCD corrections to the decoupling constant for $\alpha_s$ which relates the Minimal Supersymmetric Standard Model to Quantum Chromodynamics with five or six active flavours. The new results can be used to study the…
In the framework of analytic approach to QCD the nonperturbative contributions in running coupling of strong interaction up to 4-loop order are obtained in an explicit form. For all $Q>\Lambda$ they are shown to be represented in the form…
The baryon static potential is calculated in the framework of field correlator method and is shown to match the recent lattice results. The effects of the nonzero value of the gluon correlation length are emphasized.
We report on the status of a direct computation of the time-like splitting functions at next-to-next-to-leading order in QCD. Time-like splitting functions govern the collinear kinematics of inclusive hadron production and the evolution of…
The structure of leading nonperturbative corrections to the static Coulomb potential in QCD at small distances is analyzed. We argue in favor of the correction linearly dependent on distance and remark that lattice measurements of static…
We compute the energy spectrum of gluelumps defined as gluonic excitations bound to a localized, static octet source. We are able to reproduce the nontrivial ordering of the spin-parity levels and show how this is related to the non-abelian…
We present a method for computing hybrid static quark-antiquark potentials in lattice QCD based on Laplace trial states. They are formed by eigenvector components of the covariant lattice Laplace operator and their covariant derivatives.…
The effective potential of scalar QED is computed analytically up to two loops in the Landau gauge. The result is given in 4-epsilon dimensions using minimal subtraction and epsilon-expansions. In three dimensions, our calculation is…
We study three subjects on quark confinement in hadrons in SU(3)$_{\rm c}$ lattice QCD. From the accurate lattice calculation for more than 300 different patterns of three-quark (3Q) systems, we find that the static 3Q potential is well…
We compute the suppression of bottomonium in the quark-gluon plasma using the three-loop QCD static potential. The potential describes the spin-averaged bottomonium spectrum below threshold with a less than 1% error. Within potential…
We report results on the static quark potential in two-flavor full QCD. The calculation is performed for three values of lattice spacing $a^{-1}\approx 0.9, 1.3$ and 2.5 GeV on $12^3{\times}24, 16^3{\times}32$ and $24^3{\times}48$ lattices…
Using the framework of QCD sum rules we predict the twist-3 contribution to the second moment of the polarized nucleon structure function $g_2(x)$. As the relevant local operator depends explicitely on the gluon field, we employ a recently…
Using pNRQCD and known results for the field strength correlator, we calculate the ultrasoft contribution to the QCD static energy of a quark-antiquark pair at short distances at NNNNLO in alpha_s. At the same order, this provides the…
We consider the singular behaviour of one-loop QCD matrix elements when several external partons become simultaneously parallel. We present a new factorization formula that describes the singular collinear behaviour directly in colour…