Dark Strings and their Couplings to the Standard Model
  We consider the Standard Model extended by a hidden sector U(1)_X symmetry
that is spontaneously broken at the TeV scale by the vacuum expectation value
of an additional scalar field. We study "dark string" solutions in this model
and their properties due to the Higgs portal and gauge kinetic mixing
operators. We find that dark strings effectively interact with Higgs and Z
bosons by linear couplings, and with leptons and baryons via Aharonov-Bohm
couplings, thus possibly leading to new cosmological constraints on dark matter
models with spontaneously broken extra U(1) symmetry factors.
