Low-energy electron-positron collider to search and study (μ+μ−) bound state Anton Bogomyagkov, Vladimir Druzhinin, Eugene Levichev, Alexander Milstein and Sergej Sinyatkin EPJ Web of Conferences, 181 (2018) 01032 Published online: 25 June 2018 DOI: 10.1051/epjconf/201818101032