More on the flavor dependence of mϱ/fπ

In previous work, [arXiv:1905.01909], we have calculated the mϱ/fπ ratio in the chiral and continuum limit for SU(3) gauge theory coupled to Nf = 2, 3, 4, 5, 6 fermions in the fundamental representation. The main result was that this ratio displays no statistically significant Nf-dependence. In the present work we continue the study of the Nf-dependence by extending the simulations to Nf = 7, 8, 9, 10. Along the way we also study in detail the Nf-dependence of finite volume effects on low energy observables and a particular translational symmetry breaking unphysical, lattice artefact phase specific to staggered fermions.

Lattice study of QCD at finite chiral density: topology and confinement

In this paper we study the properties of QCD at nonzero chiral density $$\rho _5$$ ρ 5 , which is introduced through chiral chemical potential $$\mu _5$$ μ 5 . The study is performed within lattice simulation of QCD with dynamical rooted staggered fermions. We first check that $$\rho _5$$ ρ 5 is generated at nonzero $$\mu _5$$ μ 5 and in the chiral limit observe $$\rho _5 \sim \varLambda _{QCD}^2 \mu _5$$ ρ 5 ∼ Λ QCD 2 μ 5 . We also test the possible connection between confinement and topological fluctuations. To this end, we measured the topological susceptibility $$\chi _{\mathrm{top}}$$ χ top and string tension $$\sigma $$ σ for various values of $$\mu _5$$ μ 5 . We observed that string tension grows with $$\mu _5$$ μ 5 . It seems that topological susceptibility also rises with $$\mu _5$$ μ 5 , but to state this more reliably the uncertainties should be reduced. We believe that our results indicate possible connection between topological fluctuations and the strength of confinement.