  We investigate the magnetic excitation spectrum in the helical state of a
noncentrosymmetric superconductor with inversion symmetry breaking and strong
Rashba spin-orbit coupling. For this purpose, we derive the general expressions
of the dynamical spin response functions under the presence of strong Rashba
splitting of conduction bands, superconducting gap, and external field which
lead to stabilization of Cooper pairs with finite overall momentum in a helical
state. The latter is characterized by momentum space regions of paired and
unpaired states with different quasiparticle dispersions. The magnetic response
is determined by i) excitations within and between both paired and unpaired
regions ii) anomalous coherence factors and iii) additional spin matrix
elements due to helical Rashba spin texture of bands. We show that as a
consequence typical correlated real space and spin space anisotropies appear in
the dynamical susceptibility which would be observable as a characteristic
fingerprint for a helical superconducting state in inelastic neutron scattering
investigations.
