Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · hep-lat/9808004

Topological properties of full QCD at the phase transition

B. Alles·M. D'Elia·A. Di Giacomo·P. W. Stephenson
View original source ↗Read source document ↗Export metadata ↓

Abstract

We investigate the topological properties of the QCD vacuum with 4 flavours of dynamical staggered fermions at finite temperature. To calculate the topological susceptibility we use the field-theoretical method. As in the quenched case, a sharp drop is observed for the topological susceptibility across the phase transition.

Explore related subjects

hep-lathep-phhep-th

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

B. Alles, M. D'Elia, A. Di Giacomo, P. W. Stephenson. 1998-08-06. Topological properties of full QCD at the phase transition. https://doi.org/10.1016/s0920-5632(99)85123-8

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Extraction of spectral densities from lattice correlators: decoupling signal from noise

We expand the treatment of the problem of the extraction of smeared spectral densities from Euclidean correlators introduced in [Phys. Rev. D 99, 094508], providing an alternative which does not rely on the Backus-Gilbert regularization. This is possible due to the observation that the solution can be decomposed into a sum of terms, in the spirit of the singular value decomposition, where those with the largest contribution to the statistical noise happen to contribute the least to the central value of the smeared spectral density. The analysis of the systematics of the inverse problem is then shifted to finding the optimal truncation of such summation, so that the signal is saturated before the noise explodes. We scrutinise the performance and systematics of this approach either as a standalone procedure, or to complement the stability analysis required to extrapolate the unbiased result in the Backus-Gilbert regulated version of the solution.

hep-lat↗
arXiv2026

Excited-State Effects in Nucleon Sigma Terms from a Variational Analysis

We investigate excited-state effects in nucleon sigma-terms in lattice QCD using twisted-mass clover-improved fermion ensembles. We study correlation functions with nucleon and multihadron nucleon-$σ$-meson interpolating operators. The analysis is performed using three gauge ensembles, including one ensemble simulated with two degenerate light, a strange, and a charm quark with quark masses tuned to approximately their physical value. We solve the generalized eigenvalue problem that arises from the matrix of correlators and show that the three-point function for the light sigma-term obtained using the optimal linear combination of interpolating operators has substantially reduced time dependence without loss of statistical precision. We apply Laplace filtering and investigate residual excited-state contributions in the extraction of $σ_{πN}$. Using the same optimal linear combination of correlators as for $σ_{πN}$ for the strange sigma-term we also observe suppressed excited state contributions over an extended range of source--sink time separations. For the charm sigma-term, we observe negligible time dependence within the large statistical uncertainties, and these improvements show no significant effect.

hep-lat↗
arXiv2026

Ergodic topology sampling toward the continuum with Stochastic Normalizing Flows

In this work we provide numerical evidence that topological freezing in $\mathrm{SU}(3)$ Yang-Mills theory can be mitigated with a flow-based approach, as tested at lattice spacings as fine as 0.03~fm. We do so by analyzing the scaling of the costs of a computational strategy based on the combination of open boundary conditions and Stochastic Normalizing Flows. We show that the integrated autocorrelation time of the squared topological charge and the statistical uncertainty on the topological susceptibility remain under control throughout the explored parameter range with currently available computational resources. This marks an important step toward the use of even more efficient flow-based architectures for ergodic sampling of topology in state-of-the-art lattice gauge theory calculations.

hep-lat↗