Search for Z′, vacuum (in)stability and hints of high-energy structures Elena Accomando, Claudio Corianò, Luigi Delle Rose, Juri Fiaschi, Carlo Marzo and Stefano Moretti EPJ Web Conf., 129 (2016) 00007 Published online: 25 November 2016 DOI: 10.1051/epjconf/201612900007