  We analyze the near-collinear limit of the null polygonal hexagon super
Wilson loop in the planar N = 4 superYang-Mills theory. We focus on its
Grassmann components which are dual to next-to-maximal helicity-violating
(NMHV) scattering amplitudes. The kinematics in question is studied within a
framework of the operator product expansion that encodes propagation of
excitations on the background of the color flux tube stretched between the
sides of Wilson loop contour. While their dispersion relation is known to all
orders in 't Hooft coupling from previous studies, we find their form factor
couplings to the Wilson loop. This is done making use of a particular
tessellation of the loop where pentagon transitions play a fundamental role.
Being interested in NMHV amplitudes, the corresponding building blocks carry a
nontrivial charge under the SU(4) R-symmetry group. Restricting the current
consideration to twist-two accuracy, we analyze two-particle contributions with
a fermion as one of the constituents in the pair. We demonstrate that these
nonsinglet pentagons obey bootstrap equations that possess consistent solutions
for any value of the coupling constant. To confirm the correctness of these
predictions, we calculate their contribution to the super Wilson loop
demonstrating agreement with recent results to four-loop order in 't Hooft
coupling.
