TY  - EJOUR
AU  - Bruno, Mattia
AU  - Finkenrath, Jacob
AU  - Knechtli, Francesco
AU  - Leder, Bjoern
AU  - Sommer, Rainer
TI  - On the Effects of Heavy Sea Quarks at Low Energies
IS  - WUP-14-11
M1  - PUBDB-2014-04035
M1  - WUP-14-11
M1  - DESY 14-190
M1  - SFB-CPP-14-78
M1  - arXiv:1410.8374
PY  - 2014
AB  - We present a factorisation formula for the dependence of light hadron masses and low energy hadronic scales on the mass M of a heavy quark: apart from an overall factor Q, ratios such as r<sub>0</sub>(M)/r<sub>0</sub>(0) are computable in perturbation theory at large M. The mass-independent factor Q is obtained from the theory in the limit M→0 and the decoupled theory with the heavy quark removed. The perturbation theory part is stable concerning different loop orders and our non-perturbative results match on quantitatively to the perturbative prediction. Upon taking ratios of different hadronic scales at the same mass, the perturbative function drops out and the ratios are given by the decoupled theory up to M<sup>−2</sup> corrections. Our present numerical results are obtained in a model calculation where there are no light quarks and a heavy doublet of quarks is decoupled. They are limited to masses a factor two below the charm. This is not large enough to see the M<sup>−2</sup> scaling predicted by the theory, but it is sufficient to verify - in the continuum limit - that the sea quark effects of quarks with masses around the charm mass are very small.
LB  - PUB:(DE-HGF)25 ; PUB:(DE-HGF)15
UR  - https://bib-pubdb1.desy.de/record/191847
ER  -