Abstract
The quark-connected and the quark-disconnected Wick contractions contribut- ing to the pion’s scalar form factor are computed in the two and in the three flavour chiral effective theory at next-to-leading order. While the quark-disconnected contribution to the form factor itself turns out to be power-counting suppressed its contribution to the scalar radius is of the same order of magnitude as the one of the quark-connected contribution. This result underlines that neglecting quark-disconnected contributions in simulations of lattice QCD can cause significant systematic effects. The technique used to derive these predictions can be applied to a large class of observables relevant for QCD-phenomenology.
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ArXiv ePrint: 1110.4859
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Jüttner, A. Revisiting the pion’s scalar form factor in chiral perturbation theory. J. High Energ. Phys. 2012, 7 (2012). https://doi.org/10.1007/JHEP01(2012)007
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DOI: https://doi.org/10.1007/JHEP01(2012)007