  Linear Stark effect of roton transition, experimentally observed through
microwave absorption in He-II (superfluid He) in the presence of varying
external electric field, is critically analysed. We find that: (i) The effect
cannot be explained in terms of conventional microscopic theory (CMT) of He-II
which presumes the existence of p = 0 condensate and concludes that He atoms
even at T = 0 have random motions and mutual collisions which do not support
the basic factor (viz. an ordered arrangement of atomic electric dipoles)
needed for its occurrence. (ii) The desired order is concluded, rather, by a
non-conventional microscopic theory (NCMT) as an intrinsic property of He-II.
Accordingly, all atoms in He-II define a closepacked arrangement of their wave
packets (CPA-WP) with identically equal nearest neighbour distance (d), per
particle zero-point energy ({\epsilon}0 = h2/8md2) and equivalent momentum,
h/2d. (iii) The CPA-WP prevent atoms from having relative motions and mutual
collisions capable of disturbing any order of atomic dipoles. As such the NCMT
and the observed Stark effect have strong mutual support; whereas the former
concludes CPA-WP necessary for the occurrence of the effect, the latter
strengthens the experimental support for the former, which means that
theobservation does not support the presence of p = 0 condensate in He-II.
