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arXiv · 1611.03523

Scale-setting, flavour dependence and chiral symmetry restoration

Daniele Binosi·Craig D. Roberts·Jose Rodriguez-Quintero
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Abstract

We determine the flavour dependence of the renormalisation-group-invariant running interaction through judicious use of both unquenched Dyson-Schwinger equation and lattice results for QCD's gauge-sector two-point functions. An important step is the introduction of a physical scale setting procedure that enables a realistic expression of the effect of different numbers of active quark flavours on the interaction. Using this running interaction in concert with a well constrained class of dressed--gluon-quark vertices, we estimate the critical number of active lighter-quarks above which dynamical chiral symmetry breaking becomes impossible: $n_f^{\rm cr}\approx 9$; and hence in whose neighbourhood QCD is plausibly a conformal theory.

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Daniele Binosi, Craig D. Roberts, Jose Rodriguez-Quintero. 2016-11-10. Scale-setting, flavour dependence and chiral symmetry restoration. https://doi.org/10.1103/physrevd.95.114009

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