Scales of mass generation for Majorana neutrinos ( as well as quarks and leptons ) can be probed from high energy 2 \rightarrow n inelastic scattering involving a multiple longitudinal gauge boson final state .
We demonstrate that the unitarity of 2 \rightarrow n scattering puts the strongest new upper limit on the scale of fermion mass generation , independent of the electroweak symmetry breaking scale v = ( \sqrt { 2 } G _ { F } ) ^ { - \frac { 1 } { 2 } } .
Strikingly , for Majorana neutrinos ( quarks and leptons ) , we find that the strongest 2 \rightarrow n limits fall in a narrow range , 136 - 170 TeV ( 3 - 107 TeV ) with n = 20 - 24 ( n = 2 - 12 ) , depending on the observed fermion masses .
Physical implications are discussed .