The book "Leap 2011" documents the proceedings of the International Conference Leap'11 (Low Energy Antiproton Physics), which took place from April 27 to May 1, 2011, in Vancouver, Canada. This conference was organized by TRIUMF, the national laboratory for particle and nuclear physics in Canada. Over the past 50 years, research on exotic atoms has made significant progress, leading to a deeper understanding of fundamental interactions and symmetries. This volume contains research papers that highlight both current achievements and future possibilities in this interdisciplinary field of atomic, nuclear, and particle physics. The contributions are thematically organized according to the sessions of the conference and are aimed at researchers as well as advanced students.