TY  - CONF
AU  - Varnhorst, L.
AU  - Durr, S.
AU  - Fodor, Z.
AU  - Hoelbling, C.
AU  - Krieg, S.
AU  - Lellouch, L.
AU  - Portelli, A.
AU  - Sastre, A.
AU  - Szabo, Kalman
TI  - Up and down quark masses and corrections to Dashen's theorem from lattice QCD and quenched QED
VL  - LATTICE2016
SN  - 1824-8039
CY  - Trieste
PB  - SISSA
M1  - FZJ-2017-01490
T2  - Proceedings of Science LATTICE2016 200
SP  - 200
PY  - 2017
AB  - We present a determination of the corrections to Dashen's theorem and of the individual up and down quark masses from a lattice calculation based on quenched QED and $N_f =2+1$ QCD simulations with 5 lattice spacings down to 0.054 fm. The simulations feature lattice sizes up to 6 fm and average up-down quark masses all the way down to their physical value. For the parameter which quantifies violations to Dashens's theorem we obtain $\epsilon=0.73(2)(5)(17)$, where the first error is statistical, the second is systematic, and the third is an estimate of the QED quenching error. For the light quark masses we obtain, $m_u=2.27(6)(5)(4) \, MeV$ and $m_d=4.67(6)(5)(4) \, MeV$ in the $\overline{MS}$ scheme at $2 \, GeV$ and the isospin breaking ratios $m_u/m_d=0.485(11)(8)(14)$, $R=38.2(1.1)(0.8)(1.4)$ and $Q=23.4(0.4)(0.3)(0.4)$. Our results exclude the $m_u=0$ solution to the strong CP problem by more than 24 standard deviations.
T2  - 34th annual International Symposium on Lattice Field Theory
CY  - 24 Jul 2016 - 30 Jul 2016, Southampton (UK)
Y2  - 24 Jul 2016 - 30 Jul 2016
M2  - Southampton, UK
LB  - PUB:(DE-HGF)8 ; PUB:(DE-HGF)7
UR  - https://juser.fz-juelich.de/record/827319
ER  -