2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/22727This paper has been withdrawn by the authors. We have discovered an error in our estimate of c, leading to a larger discrepancy with the exact result. This prevents us to judge the quality of the approximation from its leading order prediction, and we withdraw the paper until we have completed the next to leading order calculationThis paper has been withdrawnCondensed MatterHigh Energy Physics - PhenomenologyHigh Energy Physics - Theorytext