Do you want to publish a course? Click here

The lattice gluon propagator in renormalizable $xi$ gauges

148   0   0.0 ( 0 )
 Added by Daniele Binosi
 Publication date 2015
  fields
and research's language is English




Ask ChatGPT about the research

We study the SU(3) gluon propagator in renormalizable $R_xi$ gauges implemented on a symmetric lattice with a total volume of (3.25 fm)$^4$ for values of the guage fixing parameter up to $xi=0.5$. As expected, the longitudinal gluon dressing function stays constant at its tree-level value $xi$. Similar to the Landau gauge, the transverse $R_xi$ gauge gluon propagator saturates at a non-vanishing value in the deep infrared for all values of $xi$ studied. We compare with very recent continuum studies and perform a simple analysis of the found saturation with a dynamically generated effective gluon mass.



rate research

Read More

We present explicit numerical evidence of reflection-positivity violation for the lattice Landau gluon propagator in three-dimensional pure SU(2) gauge theory. We use data obtained at very large lattice volumes (V = 80^3, 140^3) and for three different lattice couplings in the scaling region (beta = 4.2, 5.0, 6.0). In particular, we observe a clear oscillatory pattern in the real-space propagator C(t). We also verify that the (real-space) data show good scaling in the range t in [0,3] fm and can be fitted using a Gribov-like form. The violation of positivity is in contradiction with a stable-particle interpretation of the associated field theory and may be viewed as a manifestation of confinement.
We discuss the subtleties concerning the lattice computation of the ghost propagator in linear covariant gauges, and present preliminary numerical results.
We address the interpretation of the Landau gauge gluon propagator at finite temperature as a massive type bosonic propagator. Using pure gauge SU(3) lattice simulations at a fixed lattice volume $sim(6.5fm)^3$, we compute the electric and magnetic form factors, extract a gluon mass from Yukawa-like fits, and study its temperature dependence. This is relevant both for the Debye screening at high temperature $T$ and for confinement at low $T$.
We calculate loop contributions up to four loops to the Landau gauge gluon propagator in numerical stochastic perturbation theory. For different lattice volumes we carefully extrapolate the Euler time step to zero for the Langevin dynamics derived from the Wilson action. The one-loop result for the gluon propagator is compared to the infinite volume limit of standard lattice perturbation theory.
We consider the interquark potential in the one-gluon-exchange (OGE) approximation, using a fully nonperturbative gluon propagator from large-volume lattice simulations. The resulting VLGP potential is non-confining, showing that the OGE approximation is not sufficient to describe the infrared sector of QCD. Nevertheless, it represents an improvement over the perturbative (Coulomb-like) potential, since it allows the description of a few low-lying bound states of charmonium and bottomonium. In order to achieve a better description of these spectra, we add to VLGP a linearly growing term. The obtained results are comparable to the corresponding ones in the Cornell-potential case. As a byproduct of our study, we estimate the interquark distance for the considered charmonium and bottomonium states.
comments
Fetching comments Fetching comments
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا