A Geometric Classification of the Five Recurrent Mass Windows in LENR Transmutation Data

This poster presents a phenomenological geometric framework for organizing recurrent mass patterns observed in Low Energy Nuclear Reaction (LENR) transmutation data. Analyses of multiple LENR transmutation datasets, most notably by Nagel, have suggested the apparent presence of five relatively narrow mass regions across the periodic table, centered approximately at A = 12, 32, 66, 120, and 198. While the physical origin of these structures remains an open question, their recurrence across different experimental configurations suggests that they may reflect an underlying structural regularity. In this work, we introduce a dimensionless geometric parameter defined as the ratio between nuclear diameter and the electron Compton wavelength, and anchor five reference values to the empirically observed mass windows. A simple distance metric is then used to classify nuclei according to their proximity to these reference values. The resulting framework provides a compact and reproducible way to organize transmutation data without assuming any specific microscopic mechanism. The approach is complementary to existing theoretical models, such as the Widom–Larsen optical potential description, and is intended as a descriptive tool for comparing datasets and guiding further experimental and theoretical investigation. This poster summarizes the methodology, the classification scheme, and its application across the periodic table. The present contribution is associated with a companion paper that will be submitted to conference proceedings.