Pineda, Antonio (Pineda Ruiz)2009-10-062009-10-0620021050-2947https://hdl.handle.net/2445/9570We obtain the next-to-next-to-leading-logarithmic renormalization-group improvement of the spectrum of hydrogenlike atoms with massless fermions by using potential NRQED. These results can also be applied to the computation of the muonic hydrogen spectrum where we are able to reproduce some known double logarithms at O(m¿s6). We compare with other formalisms dealing with logarithmic resummation available in the literature.5 p.application/pdfeng(c) The American Physical Society, 2002Electrodinàmica quànticaTeoria de camps (Física)Pertorbació (Dinàmica quàntica)Nivells d'energia (Mecànica quàntica)Quantum electrodynamicsQuantum field theoryPerturbation (Quantum dynamics)Energy levels (Quantum mechanics)info:eu-repo/semantics/article508381info:eu-repo/semantics/openAccess