English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present results concerning the non-perturbative evaluation of therenormalisation constant for the quark field, $Z_q$, from lattice simulationswith twisted mass quarks and three values of the lattice spacing. We use theRI'-MOM scheme. $Z_q$ has very large lattice spacing artefacts; it isconsidered here as a test bed to elaborate accurate methods which will be usedfor other renormalisation constants. We recall and develop the non-perturbativecorrection methods and propose tools to test the quality of the correction.These tests are also applied to the perturbative correction method. We checkthat the lattice spacing artefacts scale indeed as $a^2p^2$. We then study therunning of $Z_q$ with particular attention to the non-perturbative effects,presumably dominated by the dimension-two gluon condensate $\VEV{A^2}$ inLandau gauge. We show indeed that this effect is present, and not small. Wecheck its scaling in physical units confirming that it is a continuum effect.It gives a $\sim 4%$ contribution at 2 GeV. Different variants are used inorder to test the reliability of our result and estimate the systematicuncertainties. Finally combining all our results and using the known Wilsoncoefficient of $\VEV{A^2}$ we find $g^2(\mu^2) \VEV{A^2}_{\mu^2\; CM} =  2.01(11)(^{+0.61}_{- 0.73}) \;\mathrm {GeV}^2$ at $\mu=10\, \mathrm{GeV}$, infair agreement within uncertainties with the value indepently extracted fromthe strong coupling constant.

Renormalisation of quark propagators from twisted-mass lattice QCD at $N_f$=2