Related papers: String-breaking in quenched QCD
We present results for the static-light meson from unquenched lattice QCD. The unquenched gauge configurations were generated using the non-perturbatively improved clover action. At the fixed lattice spacing of 0.1 fm the lightest sea quark…
The significant heavy threshold effect is found in the supersymmetric SU(5) model with two adjoint scalars, one of which is interpreted as a massive string mode decoupled from the lower-energy particle spectra. This threshold related with…
We study some features of the confining string connecting a quark-anti-quark pair in Yang-Mills theory. Monte Carlo investigations of the flux tube between two static quarks in the fundamental representation show that its thickness…
We present a preliminary computation of potentials between two static quarks in $n_f=2$ QCD with O(a) improved Wilson fermions. We explore different smearing choices (HYP, HYP2 and APE) and their effect on the signal to noise ratio in the…
We study quantum electrodynamics in 1+1 dimensions in the light--front frame using numerical methods. We analyze confinement and charge screening which are key features of this system. By direct analysis of wavefunctions of bound states in…
We investigate quantum chromodynamics with two colors at nonvanishing density using Dyson-Schwinger equations. Lattice methods do not have a complex action problem in this theory. Thus, we can benchmark our results and the effect of…
The QCD string model is employed to evaluate the masses of orbitally and radially excited heavy-light mesons and lightest hybrids in the spectrum of charmonium and bottomonium. The number of parameters of the model is reduced to only seven…
A detailed study is made of four dimensional SU(2) gauge theory with static adjoint ``quarks'' in the context of string breaking. A tadpole-improved action is used to do simulations on lattices with coarse spatial spacings $a_s$, allowing…
Using the QCD spectral sum rule approach we investigate different currents with $J^{PC}=1^{++}$, which could be associated with the $X(3872)$ meson. Our results indicate that, with a four-quark or molecular structure, it is very difficult…
We consider the phenomenon of string breaking in the context of the spatial Wilson loops using the gauge/string duality. In particular, we discuss the impact of light flavors on the pseudopotential. We also introduce the notion of the…
For lattice QCD with two sea quark flavours we compute the static quark antiquark potential V(R) in the regime where string breaking is expected. In order to increase statistics, we make full use of the lattice information by including all…
Field distributions generated by static quark-antiquark and QQQ sources are calculated analytically in the framework of Gaussian (bilocal) approximation of Field Correlator Method (FCM). Special attention is paid to the QQQ system and…
String breaking is a central dynamical process in theories featuring confinement, where a string connecting two charges decays at the expense of the creation of new particle-antiparticle pairs. Here, we show that this process can also be…
Thermodynamics of a heavy quark-antiquark pair in SU(3)-QCD is studied below the deconfinement critical temperature, $T_c$. In the quenched case, a model of the string passing through heavy valence gluons yields a correct estimate of $T_c$…
Recent results for the spectrum of light hadrons provide clear evidence for the failure of quenched QCD and encouraging signs that simulations with dynamical sea quarks rectify some of the discrepancies, although string breaking has not yet…
Results from a comprehensive new analysis on the excitation spectrum of the QCD string are presented. A rapid onset of string formation is observed in the spectrum on a length scale of 2 fm, with Dirichlet boundary conditions. The crossover…
We propose gauging matrix models of string theory to eliminate unwanted non-singlet states. To this end we perform a discretised light-cone quantisation of large N gauge theory in 1+1 dimensions, with scalar or fermionic matter fields…
The potential between static-light mesons forming a meson-meson or a meson-antimeson system is calculated in quenched and unquenched SU(3) gauge theory. We use the Sheikholeslami-Wohlert action and statistical estimators of light quark…
We introduce a variational ansatz based on Gaussian states for (1+1)-dimensional lattice gauge models. To this end we identify a set of unitary transformations which decouple the gauge degrees of freedom from the matter fields. Using our…
The effect of using smeared sink operators on the hadron spectrum is studied for quenched twisted mass lattice QCD with up, down, and strange quarks. Gaussian smearing is used for quark fields, and stout link smearing for gauge fields.…