A new method, based on comparing isotopic yield ratios measured at forward and sideward polar angles and on cross-bombarding heavy nuclei with different neutron-to-proton ratios, is used to quantify the stopping power of nuclear matter in heavy-ion collisions. For central collisions of isotopically separated 124,129Xe+112,124Sn at 100~MeV/nucleon bombarding energy, measured with the 4π multidetector INDRA at GSI, a moderate transparency is deduced for hydrogen isotopes, whereas for heavier fragmentation products with atomic number Z≥3 a high transparency exceeding 50\% is observed. An anomalously large transparency is found for alpha particles, and possible explanations are presented.
@article{arxiv.2412.11648,
title = {Isotopic Transparency in Central Xe+Sn Collisions at 100 MeV/nucleon},
author = {Arnaud Le Fèvre and Abdelouahad Chbihi and Quentin Fable and Tom Génard and Jerzy Łukasik and Wolfgang Trautmann and Ketel Turzó and Rémi Bougault and Sylvie Hudan and Olivier Lopez and Walter F. J. Müller and Carsten Schwarz and Concettina Sfienti and Giuseppe Verde and Mariano Vigilante and Bogdan Zwiegliński},
journal= {arXiv preprint arXiv:2412.11648},
year = {2025}
}