Dynamical twisted mass fermions with light quarks: simulation and analysis details

Abstract

In a recent paper [1] we presented precise lattice QCD results of our European Twisted Mass Collaboration (ETMC). They were obtained by employing two mass-degenerate flavours of twisted mass fermions at maximal twist. In the present paper we give details on our simulations and the computation of physical observables. In particular, we discuss the problem of tuning to maximal twist, the techniques we have used to compute correlators and error estimates. In addition, we provide more information on the algorithm used, the autocorrelation times and scale determination, the evaluation of disconnected contributions and the description of our data by means of chiral perturbation theory formulae.

Kaon mixing beyond the SM from Nf = 2 tmQCD and model independent constraints from the UTA

“…[43]- [45] and implemented in refs. [46] and [47]) to guarantee the O(a)-improvement of physical observables and get rid of all the unwanted leading chirally enhanced cutoff effects. In the gauge sector the tree-level improved action proposed in ref.…”

Lattice QCD study of the radiative decays J/ψ → η c γ and h c → η c γ

“…JHEP01 (2013) [30,31]). Data obtained at different β's are rescaled by using the Sommer parameter r 0 /a, and the overall lattice spacing is fixed by matching f π obtained on the lattice with its physical value, leading to r 0 = 0.440(12) fm (c.f.…”

“…Similarly to our recent publication [29], we use the gauge field configurations produced by ETM Collaboration [30,31] employing the maximally twisted mass QCD [32], the details of which are summarized in table 1. The masses of charmonia are extracted from the following correlation functions:…”

“…In practice r = 1 and m cr is the same as the one used in the production of the gauge field configurations [30,31]. Finally, ∇ µ and ∇ * µ are the usual forward and backward derivatives on the lattice.…”

Lattice QCD determination of m b , f B and f Bs with twisted mass Wilson fermions

“…The calculation is based on the N f = 2 gauge field configurations generated by the European Twisted Mass (ETM) Collaboration with the tree-level improved Symanzik gauge action [9] and the twisted mass quark action [10] at maximal twist, discussed in detail in [11][12][13][14][15][16][17]. We simulated N f = 2 mass-degenerate dynamical quarks, whose mass is eventually extrapolated to the physical isospin averaged mass of the up and down quarks, m u/d .…”