Scattering s-channel
= Scattering s-channel
{title2=$s=(p_1+p_2)^2$}
= s-channel
{c}
{synonym}
The direct channel combines the two incoming <four-momentum> vectors. A one-particle <pole> in this channel has the intermediate particle's squared <mass> equal to $s$. Imaginary <rapidity> differences can satisfy this <mass> relation for a <bound state> even though there is no <pole> at real physical scattering <rapidity>.