Journal Article/Contribution to a conference proceedings/Contribution to a book

FZJ-2025-05560

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Error Scaling of Sea Quark Isospin-Breaking Effects

Altherr, A. ; Campos, I. ; Cotellucci, A. (Corresponding author)FZJ* ; Gruber, R. ; Harris, T. ; Marinkovic, M. ; Parato, L. ; Patella, A. ; Rosso, S. ; Tavella, P.

2025
Sissa Medialab Trieste, Italy

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Please use a persistent id in citations: doi:10.22323/1.466.0116

Abstract: Sea-quark isospin-breaking effects (IBE) are difficult to compute since they require the evaluation of all-to-all propagators. However, the quest for high-precision calculations motivates a detailed study of these contributions. There are strong arguments that the stochastic error associated with these quantities should diverge in the continuum and infinite-volume limit, resulting in a possible bottleneck for the method. In this work, we present the study of the error scaling for these quantities using $N_f=3$ $O(a)$-improved Wilson fermions QCD with C-periodic boundary conditions in space, a pion mass $M_{\pi}=400$ MeV, a range of lattice spacings $a=0.05, 0.075, 0.1$ fm, and volumes $L=1.6, 2.4, 3.2$ fm. The analysis of the error as a function of the number of stochastic sources shows that we reach the gauge error for the dominant contributions. The errors do not show the leading order divergence $1/a$ for strong-IBE and $1/a^2$ for electromagnetic IBE, in the considered range of lattice spacings. On the other hand, our data are consistent with the predicted leading divergence $\sqrt{V}$.

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Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)

Research Program(s):

1. 5111 - Domain-Specific Simulation & Data Life Cycle Labs (SDLs) and Research Groups (POF4-511) (POF4-511)
2. GRK 2575 - GRK 2575: Überdenken der Quantenfeldtheorie (417533893) (417533893)

Appears in the scientific report 2025

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