  In this perspective we discuss recent theoretical and experimental concepts
giving a route to a better understanding of conventional and unconventional
pairing mechanisms between opposite-spin fermions arising in one-dimensional
mesoscopic systems. With special attention, we focus on the problem of
experimental detectability of correlations between particles. We argue that
state-of-the-art experiments with few ultracold fermions may finally break an
impasse and give pioneering and unquestionable verification of the existence of
correlated pairs with non-zero center-of-mass momentum.
