Zone-selection effect of photoelectron intensity distributions in the nonsymmorphic system RAlSi ( R=Ce or Nd)

We investigate the electronic structures of noncentrosymmetric Weyl semimetals $R\mathrm{AlSi}$ ($R$ = Ce and Nd) using soft x-ray angle-resolved photoemission spectroscopy. We find that the photoelectron intensity distribution observed in the momentum-resolved electronic bands is highly sensitive to the probed Brillouin zone (BZ) owing to the zone-selection effect arising from the nonsymmorphic crystal structure of $R\mathrm{AlSi}$. Our data reconstruct the photoelectron distributions varied according to the zone-selection effect and reveal comprehensive information about the electronic band structures predicted by band calculations. This detailed information enables us to experimentally trace the Weyl-cone dispersion throughout three-dimensional momentum space, providing valuable insights into the unique properties of $R\mathrm{AlSi}$.