Related papers: The Strong Coupling Constant from Hadron Structure…
Colour transparency is a cute and indispensable property of QCD as the gauge theory of strong interaction. CT tests of QCD consist of production of the perturbative small-sized hadronic state and measuring the strngth of its…
We investigate the influence of a magnetic field on the running coupling constant for a heavy-quark model in a bottom-up holographic approach. To achieve this, we employ a magnetized Einstein-Maxwell-dilaton background that captures the…
Inspired by the relation between the hadronic decay of the tau lepton and the electron-positron annihilation into hadrons, we derive new tests of perturbative QCD. We design a set of commensurate scale relations to test the self-consistency…
In the framework of perturbative QCD in the fourth order over the $\alpha_s$ coupling constant for the production of two pairs of quarks and in the model of weak binding of the quarks into meson, the analysis of the hadronic production of…
The strong-coupling constant is determined from the low-momentum region of the transverse-momentum distribution of $Z$ bosons produced through the Drell-Yan process, using predictions at third order in perturbative QCD. The analysis employs…
In order to understand QCD at the energies relevant to hadronic physics one requires analytical methods for dealing with relativistic gauge field theories at large couplings. Strongly coupled quenched QED provides an ideal laboratory for…
New predictions regarding the role of color flow in high energy Quantum Chromodynamics (QCD) processes have emerged in the last decade. In particular, the role of color flow is now being explored through many different observables; one such…
Coherence phenomena, and the non-universality of parton structure of the effective Pomeron are explained. New hard phenomena directly calculable in QCD such as diffractive electroproduction of states with $M^2\ll Q^2$ as well as new options…
The theory of the strong force, Quantum Chromodynamics (QCD) remains one of the most important ways to understand the fundamental properties of ordinary matter. However, at low momentum transfer Q2, in the regime where the strong force…
The normalization of the gluon condensate and of renormalon-related power corrections in QCD is computed under the assumption that their ``perturbative'' part dominates over any eventual extra contribution from the non-trivial vacuum. The…
We computed the static potential and Wilson loops to $O(\alpha^2)$ in perturbation theory for different lattice quark and gluon actions. In general, we find short distance lattice data to be well described by ``boosted perturbation…
A microscopic treatment of cumulative phenomena based on perturbative QCD calculations of the corresponding quark diagrams near the threshold is presented. To sum all diagrams like these the special technique based on the recurrence…
Critical behaviors of quark-hadron phase transition in high-energy heavy-ion collisions are investigated with the aim of identifying hadronic observables. The surface of the plasma cylinder is mapped onto a 2D lattice. The Ising model is…
We present a non-perturbative computation of the running of the coupling alpha_s in QCD with two flavours of dynamical fermions in the Schroedinger functional scheme. We improve our previous results by a reliable continuum extrapolation.…
We study a quantum phase transition between a phase which is topologically ordered and one which is not. We focus on a spin model, an extension of the toric code, for which we obtain the exact ground state for all values of the coupling…
We present a formalism to evaluate QCD diagrams with a single virtual gluon using a running coupling constant at the vertices. This method, which corresponds to an all-order resummation of certain terms in a perturbative series, provides a…
The QCD improved parton model is a very successful concept to treat processes in hadronic interactions, whenever large partonic transverse momenta are involved. However, cross sections diverge in the limit p_T -> 0, and the usual treatment…
We show that detector switching profiles consisting of trains of delta couplings are a useful computational tool to efficiently approximate results involving continuous switching functions, both in setups involving a single detector and…
Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of…
We derive new QCD sum rules for the axial coupling constants by considering two-point correlation functions of the axial-vector currents in a one nucleon state. The QCD sum rules tell us that the axial coupling constants are expressed by…