Related papers: Factorization of Coupling Constant in Background F…
In this work, we investigate the nature of the strong coupling constant and related physics. Through the analysis of accumulated experimental data from around the world, we employ the ability of machine learning to unravel its physical…
A compact star with superconducting quark core, the hadron crust and the mixed phase between the two is considered. The quark meson coupling model for hadron matter and the color flavor locked quark model for quark matter is used in order…
We report on calculations of the hadronic coupling constants $g_{\rho\pi\pi}$ and $g_{nn\pi}$ based on lattice QCD with four flavors of dynamical staggered fermions. By computing 2--point and 3--point Green's functions we have been able to…
We discuss the recent interpretation of quark-distribution functions in the plane transverse to the light-cone direction. Such a mapping is model independent and allows one to build up multidimensional pictures of the hadron and to develop…
Quark-hadron duality is an interesting and potentially very useful phenomenon, as it relates the properly averaged hadronic data to a perturbative QCD result in some kinematic regions. While duality is well established experimentally, our…
Nonlinear phenomena of lepton-photon interactions in external backgrounds with a generalised periodic plane-wave geometry are studied. We discuss nonlinear Compton scattering in head-on lepton-photon collisions extended properly to beyond…
We investigated the impact parameter dependence of the background field's effect on the coupling constant of the $\gamma \gamma \rightarrow l^{+} l^{-} \gamma$ process in heavy-ion collisions. The peripheral electric fields of heavy ions…
The study of Quantum Chromodynamics (QCD) at ultra-relativistic energies can be performed in a controlled environment through lepton-hadron deep inelastic scatterings. In such collisions, the high-energy partonic emissions that follow from…
We review the long term project of the ALPHA collaboration to compute in QCD the running coupling constant and quark masses at high energy scales in terms of low energy hadronic quantities. The adapted techniques required to numerically…
Using the quantum field theory approach developed in Phys. Rev. D. 93, 045002 (2016), we consider particle scattering and vacuum instability in the so-called L-constant electric field, which is a constant electric field confined between two…
The dynamics of nuclear transparency in hard nuclear reactions is studied by an expansion of the correlator of the hard scattering operator on a hadronic basis. Colour transparency appears as an effect of interference between the amplitudes…
The improved quark mass density- dependent model which includes the coupling between the quarks and a non-linear scalar field is presented. Numerical analysis of solutions of the model is performed over a wide range of parameters. The wave…
The quark-connected leading-order hadronic contributions to the running of the electromagnetic fine structure constant, $\alpha_{\rm QED}$, and the weak mixing angle, $\theta_W$, are determined by a four-flavour lattice QCD computation with…
We use an s-channel picture of hard hadronic collisions to investigate the parton distribution function for quarks at small momentum fraction x, which corresponds to very high energy scattering. We study the renormalized quark distribution…
The theory of strong interactions, QCD, is described in terms of a few parameters, namely the strong coupling constant alpha_s and the quark masses. We show how these parameters can be determined reliably using computer simulations of QCD…
We use a variational procedure to study finite density QCD in an approximation in which the interaction between quarks is modelled by that induced by instantons. We find that uniform states with conventional chiral symmetry breaking have…
This paper presents a summary of the current status of determinations of the strong coupling constant alpha_s. A detailed description of the definition, scale dependence and inherent theoretical ambiguities is given. The various physical…
We discuss scattering of fundamental matter in the planar and strong coupling limit via the AdS/CFT correspondence, generalizing the recently proposed calculation for adjoint matter due to Alday and Maldacena [arXiv:0705.0303]. Color…
The representation of quark distribution and fragmentation functions in terms of non-local operators is combined with a simple spectator model. This allows us to estimate these functions for the nucleon and the pion ensuring correct…
We analyze spectral properties of a quantum graph in the form of a ring chain with a $\delta$ coupling in the vertices exposed to a homogeneous magnetic field perpendicular to the graph plane. We find the band spectrum in the case when the…