RT Journal Article T1 The QCD topological charge and its thermal dependence: the role of the eta' A1 Gómez Nicola, Ángel A1 Ruiz De Elvira Carrascal, Jacobo A1 Vioque Rodríguez, Andrea AB We analyze the contribution of the 7/(958) meson in the first two non-trivial moments of the QCD topological charge distribution, namely, the topological susceptibility and the fourth-order cumulant of the vacuum energy density. We perform our study within U(3) Chiral Perturbation Theory up to next -to-next -to-leading order in the combined chiral and large-Ne expansion. We also describe the temperature dependence of these two quantities and compare them with previous analyses in the literature. In particular, we discuss the validity of the thermal scaling of the topological susceptibility with the quark condensate, which is intimately connected with a Ward Identity relating both quantities. We also consider isospin breaking corrections from the vacuum misalignment at leading order in the U(3) framework. PB Springer SN 1029-8479 YR 2019 FD 2019-11-14 LK https://hdl.handle.net/20.500.14352/6093 UL https://hdl.handle.net/20.500.14352/6093 LA eng NO © 2019 The Autors.We are very grateful to F. K. Guo, U. G. Meiner, J. J. Sanz-Cillero, Z. H. Guo and T. Vonk for very useful comments. Work partially supported by research contract FPA2016-75654-C2-2-P (spanish "Ministerio de Economia y Competitividad") and the Swiss National Science Foundation, project No. PZ00P2 174228. This work has also received funding from the European Union Horizon 2020 research and innovation programme under grant agreement No 824093. A. V-R acknowledges support from a fellowship of the UCM predoctoral program. NO Unión Europea. H2020 NO Ministerio de Economía y Competitividad (MINECO) NO Swiss National Science Foundation (SNSF) DS Docta Complutense RD 8 abr 2025