Searcharxiv⌕ Search

arXiv · 0710.1517

Lattice QCD with two light Wilson quarks and maximally twisted mass

Abstract

We summarise status and recent results of the European Twisted Mass collaboration (ETMC). The collaboration has generated gauge configurations for three different values of the lattice spacing smaller or equal 0.1 fm and values of the charged pseudo scalar mass as low as 300 MeV with two flavours of maximally twisted mass quarks. We provide evidence that O(a) improvement works very well with maximally twisted mass fermions and that also higher order lattice artifacts appear to be small. The currently only quantity in the light meson and baryon sector where cut-off effects are visible is the neutral pseudo scalar meson mass and we present an attempt to understand this from a theoretical point of view. We describe finite size effects and quark mass dependence of the mass and decay constant of the (charged) pseudo scalar meson with chiral perturbation theory formulae and our current estimate for the low energy constants l_{3,4} is l_3=3.44(8)(35) and l_4=4.61(4)(11). Results for the average up-down, the strange and the charm quark mass and the chiral condensate are also presented.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Carsten Urbach. 2007-10-08. Lattice QCD with two light Wilson quarks and maximally twisted mass. https://arxiv.org/abs/0710.1517

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

KEEP EXPLORING

Related papers

Jianmu-Q: Bridging Quantum Field Theory and Quantum Hardware with AI Agents

Quantum computing offers a promising approach to non-perturbative simulations of quantum field theories, particularly for real-time dynamics and systems affected by the sign problem. Yet translating continuum field theories into quantum computations remains a challenging interdisciplinary task. Here we introduce \texttt{Jianmu-Q}, a multi-agent framework that transforms natural-language descriptions of quantum field theories into quantum simulation workflows. Specialized agents handle theoretical formulation, lattice discretization, qubit mapping, and circuit design, while physical consistency checks and independent numerical calculations provide validation throughout the workflow. We benchmark the framework on three field theories of increasing complexity: the $(1+1)$-dimensional Nambu--Jona-Lasinio and Schwinger models, and a $(2+1)$-dimensional $\mathbb{Z}_2$ gauge theory. Across these systems, noiseless quantum-circuit simulations converge toward independent exact-diagonalization and tensor-network results, while selected circuits are executed on IBM quantum hardware, demonstrating an end-to-end, validation-guided approach to quantum simulation of field theories.

hep-lat↗

The hadronic-vacuum-polarization contribution to the muon anomalous magnetic moment in isospin-symmetric lattice QCD with twisted-mass fermions

We present a lattice-QCD calculation of the leading-order hadronic-vacuum-polarization (HVP) contribution to the anomalous magnetic moment of the muon in isospin-symmetric QCD. We employ the gauge configurations generated by the Extended Twisted Mass Collaboration (ETMC) with $N_f = 2 + 1 + 1$ flavors of Wilson-clover twisted-mass quarks at four lattice spacings and at values of the quark-mass parameters matching the definition of isospin-symmetric QCD given in the FLAG review 2024 and in the 2025 edition of the Muon $g-2$ Theory Initiative White Paper (WP25). After retuning the simulation parameters to precisely match these two definitions of isospin-symmetric QCD, and after carrying out an extrapolation to the continuum limit based on the data at lattice spacings $a \simeq 0.049, 0.057, 0.068$ and $0.079$~fm, and spatial lattice sizes up to $L \simeq 7.7$~fm, we obtain $a_μ^{\rm HVP, FLAG}(\rm{iso}) = (720.0 \pm 6.9) \times 10^{-10}$ and $a_μ^{\rm HVP, WP25}(\rm{iso}) = (714.8 \pm 7.4) \times 10^{-10}$. Our results, which have a relative uncertainty of about $1 \%$, agree well with the corresponding determinations by other lattice groups. After adding to our determination of $a_μ^{\rm HVP, WP25}(\rm{iso})$ the leading isospin-breaking corrections provided in the WP25, namely $a_μ^{\rm HVP, WP25}({\rm IB}) = 0.1(3.4)\times 10^{-10}$, we obtain for the full HVP the value $a_μ^{\rm HVP}= (714.9 \pm 8.1)\times 10^{-10}$. This result translates into a Standard Model prediction for the muon anomalous magnetic moment that is fully consistent with the latest result by the Fermilab Muon $g-2$ experiment and strengthens the tension between lattice QCD and data-driven (pre-CMD3) dispersive determinations.

hep-lat↗

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↗