The mini-proceedings of the 15th Meeting of the Working Group on Rad. Corrections and MC Generators for Low Energies held in Mainz on April 11, 2014, are presented. These meetings, started in 2006, have as aim to bring together experimentalists and t
heorists working in the fields of meson transition form factors, hadronic contributions to $(g-2)_mu$ and the effective fine structure constant, and development of Monte Carlo generators and Radiative Corrections for precision e+e- and tau physics.
We study the phenomenology of a Z-boson field coupled to hypercharge. The Z propagator has a non-trivial Kallen-Lehmann spectral density due to the mixing with a higher dimensional inert vector field. As a consequence detection possibilities at hadro
n colliders are reduced. We determine the range of parameters where this field can be studied at the Tevatron and the LHC through its production cross section via the Drell-Yan mechanism.
