2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/47230In the framework of the quasipotential method we calculate the contributions of the kind α^6\lnα, alpha^6 of three-photon exchange diagrams to the energy spectrum of muonium $n^3S_1$ state in the leading order on $m_e/m_μ$. Analytical expression of obtained correction for arbitrary principal quantum number is equal to (Zα)^6(m_e/m_μ)m_e(6\ln(2)-35/48)/n^3.10 pages, LaTEXHigh Energy Physics - Phenomenologytext