2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48969Possibilities for observing signals of CPT and Lorentz violation in the spectroscopy of hydrogen and antihydrogen are considered. We show that transitions between the c and d hyperfine sublevels in the 1S state can exhibit theoretically detectable effects that would be unsuppressed by powers of the fine-structure constant. This transition may therefore offer some advantages over 1S-2S two-photon spectroscopy.Latex, 12 pages, 3 figures, presented at the Meeting on CPT and Lorentz Symmetry, Indiana University, Bloomington, November 1998High Energy Physics - Phenomenologytext