0000000000589198
AUTHOR
Carsten Urbach
The η′ meson at the physical point with Nf = 2 Wilson twisted mass fermions
We present results for the η′ meson and the topological susceptibility in Nf = 2 flavour lattice QCD. The results are obtained using Wilson twisted mass fermions at maximal twist with pion masses ranging from 340 MeV down to the physical point. A comparison to literature values is performed giving a handle on discretisation effects.
Up, down, strange and charm quark masses withNf=2+1+1twisted mass lattice QCD
Abstract We present a lattice QCD calculation of the up, down, strange and charm quark masses performed using the gauge configurations produced by the European Twisted Mass Collaboration with N f = 2 + 1 + 1 dynamical quarks, which include in the sea, besides two light mass degenerate quarks, also the strange and charm quarks with masses close to their physical values. The simulations are based on a unitary setup for the two light quarks and on a mixed action approach for the strange and charm quarks. The analysis uses data at three values of the lattice spacing and pion masses in the range 210 – 450 MeV , allowing for accurate continuum limit and controlled chiral extrapolation. The quark …
Light meson physics from maximally twisted mass lattice QCD
40 pages, 5 figures, 8 tables, 3 appendix.-- PACS: 11.15.Ha; 12.38.Gc; 12.39.Fe
Two- and three-body interactions in $\varphi^4$ theory from lattice simulations
We calculate the one-, two- and three-particle energy levels for different lattice volumes in the complex $\varphi^4$ theory on the lattice. We argue that the exponentially suppressed finite-volume corrections for the two- and three-particle energy shifts can be reduced significantly by using the single particle mass, which includes the finite-size effects. We show numerically that, for a set of bare parameters, corresponding to the weak repulsive interaction, one can reliably extract the two- and three-particle energy shifts. From those, we extract the scattering length, the effective range and the effective three-body coupling. We show that the parameters, extracted from the two- and thre…
Topological susceptibility and η′ meson mass from Nf=2 lattice QCD at the physical point
In this paper we explore the computation of topological susceptibility and ${\ensuremath{\eta}}^{\ensuremath{'}}$ meson mass in ${N}_{f}=2$ flavor QCD using lattice techniques with a physical value of the pion mass as well as larger pion mass values. We observe that the physical point can be reached without a significant increase in the statistical noise. The mass of the ${\ensuremath{\eta}}^{\ensuremath{'}}$ meson can be obtained from both fermionic two point functions and topological charge density correlation functions, giving compatible results. With the pion mass dependence of the ${\ensuremath{\eta}}^{\ensuremath{'}}$ mass being flat we arrive at ${M}_{{\ensuremath{\eta}}^{\ensuremath…
Flavor-singlet meson decay constants from Nf=2+1+1 twisted mass lattice QCD
We present an improved analysis of our lattice data for the $\ensuremath{\eta}--{\ensuremath{\eta}}^{\ensuremath{'}}$ system, including a correction of the relevant correlation functions for residual topological finite size effects and employing consistent chiral and continuum fits. From this analysis we update our physical results for the masses ${M}_{\ensuremath{\eta}}=557(11{)}_{\text{stat}}(03{)}_{\ensuremath{\chi}\mathrm{PT}}\text{ }\text{ }\mathrm{MeV}$ and ${M}_{\ensuremath{\eta}}^{\ensuremath{'}}=911(64{)}_{\text{stat}}(03{)}_{\ensuremath{\chi}\mathrm{PT}}\text{ }\text{ }\mathrm{MeV}$, as well as the mixing angle in the quark flavor basis $\ensuremath{\phi}=38.8(2.2{)}_{\text{stat}}…