  We performed angle-resolved photoemission spectroscopy (ARPES) of bulk
2H-WSe$_2$ for different crystal orientations linked to each other by
time-reversal symmetry. We introduce a new observable called time-reversal
dichroism in photoelectron angular distributions (TRDAD), which quantifies the
modulation of the photoemission intensity upon effective time-reversal
operation. We demonstrate that the hidden orbital pseudospin texture leaves its
imprint onto TRDAD, due to multiple orbitals interference effects in
photoemission. Our experimental results are in quantitative agreement with both
tight-binding model and state-of-the-art fully relativistic calculations
performed using the one-step model of photoemission. While spin-resolved ARPES
probes the spin component of entangled spin-orbital texture in multiorbital
systems, we unambiguously demonstrate that TRDAD reveals its orbital pseudospin
texture counterpart.
