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Related papers: Measuring the Topological Susceptibility in a Fixe…

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In quantum field theories with topological sectors, a non-perturbative quantity of interest is the topological susceptibility chi_t. In principle it seems straightforward to measure chi_t by means of Monte Carlo simulations. However, for…

High Energy Physics - Lattice · Physics 2016-01-27 Wolfgang Bietenholz , Philippe de Forcrand , Urs Gerber

In simulations of a model with topological sectors, algorithms which proceed in small update steps tend to get stuck in one sector, especially on fine lattices. This distorts the numerical results; in particular it is not straightforward to…

High Energy Physics - Lattice · Physics 2016-10-12 Wolfgang Bietenholz , Krzysztof Cichy , Philippe de Forcrand , Arthur Dromard , Urs Gerber

The topological susceptibility is an important quantity in QCD, which can be computed using lattice methods. However, at a fine lattice spacing, or when using high quality chirally symmetric quarks, algorithms which proceed in small update…

High Energy Physics - Lattice · Physics 2016-05-30 Arthur Dromard , Wolfgang Bietenholz , Krzysztof Cichy , Marc Wagner

Topological charge susceptibility $\chi_{t}$ for pure gauge SU(3) theory at finite temperature is studied using anisotropic lattices. The over-improved stout-link smoothing method is utilized to calculate the topological charge. Near the…

High Energy Physics - Lattice · Physics 2015-11-11 Guang-Yi Xiong , Jian-Bo Zhang , Ying Chen , Chuan Liu , Yu-Bin Liu , Jian-Ping Ma

We consider models with topological sectors, and difficulties with their Monte Carlo simulation. In particular we are concerned with the situation where a simulation has an extremely long auto-correlation time with respect to the…

High Energy Physics - Lattice · Physics 2014-02-13 Irais Bautista , Wolfgang Bietenholz , Urs Gerber , Christoph P. Hofmann , Héctor Mejía-Díaz , Lilian Prado

We calculate the topological susceptibility at 2.5 Tc and 4.1 Tc in SU(3) pure Yang-Mills theory. We define topology with the help of gradient flow and we largely overcome the problem of poor statistics at high temperatures by applying a…

High Energy Physics - Lattice · Physics 2018-09-26 P. Thomas Jahn , Guy D. Moore , Daniel Robaina

We determine the topological susceptibility $\chi_t$ in two-flavor QCD using the lattice simulations at a fixed topological sector. The topological charge density is unambiguously defined on the lattice using the overlap-Dirac operator…

High Energy Physics - Lattice · Physics 2008-11-26 S. Aoki , T. W. Chiu , H. Fukaya , S. Hashimoto , T. H. Hsieh , T. Kaneko , H. Matsufuru , J. Noaki , K. Ogawa , T. Onogi , N. Yamada

In Monte Carlo simulations with a local update algorithm, the auto-correlation with respect to the topological charge tends to become very long. In the extreme case one can only perform reliable measurements within fixed sectors. We…

High Energy Physics - Lattice · Physics 2014-10-03 Urs Gerber , Irais Bautista , Wolfgang Bietenholz , Héctor Mejía-Díaz , Christoph P. Hofmann

We determine the topological susceptibility \chi at T=0 and its behaviour at finite T across the deconfining transition in pure SU(2) gauge theory. We use an improved topological charge density operator. \chi goes to zero above T_c, but…

High Energy Physics - Lattice · Physics 2008-11-26 B. Alles , M. D'Elia , A. Di Giacomo

We determine the topological susceptibility $\chi$ at T=0 in pure SU(3) gauge theory and its behaviour at finite $T$ across the deconfining transition. We use an improved topological charge density operator. $\chi$ drops sharply by one…

High Energy Physics - Lattice · Physics 2008-11-26 B. Allés , M. D'Elia , A. Di Giacomo

QCD topological susceptibility at high temperature, $\chi_t(T)$, provides an important input for the estimate of the axion abundance in the present Universe. While the model independent determination of $\chi_t(T)$ should be possible from…

High Energy Physics - Lattice · Physics 2016-09-21 J. Frison , R. Kitano , H. Matsufuru , S. Mori , N. Yamada

We present a measurement of the topological susceptibility in two flavor QCD. In this observable, large autocorrelations are present and also sizable cutoff effects have to be faced in the continuum extrapolation. Within the statistical…

High Energy Physics - Lattice · Physics 2015-06-22 Mattia Bruno , Stefan Schaefer , Rainer Sommer

We construct a few parameter approximate fixed point action for SU(2) pure gauge theory and subject it to scaling tests, via Monte Carlo simulation. We measure the critical coupling for deconfinement for lattices of temporal extent $N_t=2$,…

High Energy Physics - Lattice · Physics 2008-11-26 Thomas DeGrand , Anna Hasenfratz , Decai Zhu

We study the topological charge in $N_f=2$ QCD at finite temperature using M\"obius domain-wall fermions. The susceptibility $\chi_t$ of the topological charge defined either by the index of overlap Dirac operator or a gluonic operator is…

High Energy Physics - Lattice · Physics 2018-04-18 S. Aoki , Y. Aoki , G. Cossu , H. Fukaya , S. Hashimoto , K. Suzuki

We compute the topological susceptibility for the SU(3) Yang--Mills theory by employing the expression of the topological charge density operator suggested by Neuberger's fermions. In the continuum limit we find r_0^4 chi = 0.059(3), which…

High Energy Physics - Theory · Physics 2009-11-10 Luigi Del Debbio , Leonardo Giusti , Claudio Pica

We present a novel technique for the determination of the topological susceptibility (related to the variance of the distribution of global topological charge) from lattice gauge theory simulations, based on maximum-likelihood analysis of…

For quantum field theories with topological sectors, Monte Carlo simulations on fine lattices tend to be obstructed by an extremely long auto-correlation time with respect to the topological charge. Then reliable numerical measurements are…

The topological susceptibility of the quenched QCD vacuum is measured on large lattices for three $\beta$ values from $6.0$ to $6.4$. Charges possibly induced by $O(a)$ dislocations are identified and shown to have little effect on the…

High Energy Physics - Lattice · Physics 2009-10-22 Jeffrey Grandy , Rajan Gupta

We present a measurement of the topological susceptibility in SU(3) Yang-Mills theory through the deconfinement phase transition. An improved operator is used for the topological charge density. A drop by an order of magnitude is observed…

High Energy Physics - Lattice · Physics 2008-11-26 B. Alles , M. D'Elia , A. Di Giacomo

We study the impact of the Gradient Flow on the topology in various models of lattice field theory. The topological susceptibility $\chi_{\rm t}$ is measured directly, and by the slab method, which is based on the topological content of…

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