Constraints on disconnected contributions in ππ scattering
Autor: | Ulf-G. Meißner, Chien-Yeah Seng, Feng-Kun Guo, N. Ripunjay Acharya |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
Physics
Nuclear and High Energy Physics Chiral perturbation theory Nuclear Theory 010308 nuclear & particles physics Scattering Computer Science::Information Retrieval Computation High Energy Physics::Lattice Lattice field theory Lattice QCD 01 natural sciences High Energy Physics - Phenomenology Theoretical physics High Energy Physics - Lattice Isospin Lattice (order) 0103 physical sciences Chiral Lagrangians lcsh:QC770-798 ddc:530 lcsh:Nuclear and particle physics. Atomic energy. Radioactivity 010306 general physics Linear combination |
Zdroj: | Journal of High Energy Physics, Vol 2019, Iss 4, Pp 1-16 (2019) Journal of high energy physics 2019(4), 165 (2019). doi:10.1007/JHEP04(2019)165 Journal of High Energy Physics |
ISSN: | 1029-8479 |
Popis: | The accuracy of the lattice QCD computation of hadron-hadron scattering at low isospin depends critically on the ability to compute correlation functions with fermionic disconnected Wick contractions. This happens, for instance, in isospin $I=0$ $\pi\pi$ scattering, which receives contributions from rectangular and vacuum types of contractions among other easier calculable ones. Combining L\"{u}scher's formula and partially-quenched chiral perturbation theory, we provide precise theory predictions of the discrete energy levels extracted from specific linear combinations of lattice correlation functions corresponding to various types of contractions. Expressions are provided for extracting the unphysical low-energy constants in the partially-quenched chiral perturbation theory from the energy levels for these contractions. The predictions for the rectangular and vacuum contractions may serve as solid tests of the accuracy for existing and future lattice studies of $\pi\pi$ scattering. Comment: Version to appear in JHEP |
Databáze: | OpenAIRE |
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