  Classically forbidden regions ($\mathtt{CFRs}$) are common to both
non-relativistic quantum mechanics, and to relativistic quantum field theory.
It is known since 2001 that $\mathtt{CFR}$ contributes roughly sixteen percent
of energy to the ground state of a simple harmonic oscillator (Adunas G. Z. et
al., Gen. Relativ. Gravit., 33 (2001) 183). Similarly, quantum field theoretic
arguments yield a non-zero amplitude for a massive particle to cross the light
cone (that is, into the $\mathtt{CFR}$). The signs of these amplitudes are
opposite for fermions and antifermions. This has given rise to an erroneous
conclusion that amplitude to cross the lightcone is identically zero. This is
true as long as a measurement does not reveal the considered object to be a
particle or antiparticle. However, neutrino oscillation experiments do measure
a neutrino $\nu$, or an antineutrino $\bar\nu$. Here we show that in the
context of neutrino oscillations these observations have the potential to
resolve various short baseline anomalies for a sufficiently light lowest mass
eigenstate. In addition, we make a concrete prediction for the upcoming results
to be announced later this year by JSNS$^2$.
