Vector correlators in lattice QCD: Methods and applications

By David Bernecker, Harvey B. Meyer. 2011

203 citations recorded by the source corpus.

We discuss the calculation of the leading hadronic vacuum polarization in lattice QCD. Exploiting the excellent quality of the compiled experimental data for the e+e− → hadrons cross-section, we predict the outcome of large-volume lattice calculations at the physical pion mass, and design computational strategies for the lattice to have an impact on important phenomenological quantities such as the leading hadronic contribution to (g − 2)μ and the running of the electromagnetic coupling constant. First, the R(s) ratio can be calculated directly on the lattice in the threshold region, and we provide the formulae to do so with twisted boundary conditions. Second, the current correlator projected onto zero spatial momentum, in a Euclidean time interval where it can be calculated accurately, provides a potentially critical test of the experimental R(s) ratio in the region that is most relevant for (g − 2)μ. This observation can also be turned around: the vector correlator at intermediate distances can be used to determine the lattice spacing in fm, and we make a concrete proposal in this direction. Finally, we quantify the finite-size effects on the current correlator coming from low-energy two-pion states and provide a general parametrization of the vacuum polarization on the torus.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/6febf386c0926a9558961158038bc56ad0015e2f

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In Nuclear and High Energy Physics

Citations in the corpus

Scale Setting in Lattice QCD (2014, background): “The scale τ1 defined through [19, 20] −x0 d dx0 log CV(x0) ∣∣∣ x0=τ1 = 3.”
Leading hadronic contribution to the muon magnetic moment from lattice QCD (2020, methodology): “esult by 10 10, ie. a stands for aLO HVP 10 throughout this work. The renormalized scalar hadronic vacuum polarization function (HVP) can be extracted from zero momemtum current propagator G(t) as [42]: ( Q2) XT=2 t=0 t 2 4 (aQ)2 sin aQt 2 G(t) (63) 23 where tand G(t) are given in lattice units”
Lattice calculation of the short and intermediate time-distance hadronic vacuum polarization contributions to the muon magnetic moment using twisted-mass fermions (2022, methodology): “Following our previous works [21–23] we adopt the time momentum representation [24] and evaluate the HVP contribution to the muon anomalous magnetic moment aHVP μ as a μ = 2α 2 em ∫ ∞”