  The physics literature contains many claims that ultrashort-lived unstable
particles, such as a Higgs boson, have been observed. These claims are a matter
of applying the $5\sigma$-convention in particle physics. This paper, however,
shows that by applying this $5\sigma$-convention a category mistake is made, by
which a pure reasoning is passed off as an observation. Not only are these two
fundamentally different primitive notions at the very basis of science, but the
pure reasoning in question is also weaker than an observation: what we have in
each case is that the existence of the ultrashort-lived unstable particle is
inferred to the best explanation, but that does absolutely not merit the
stronger claim that the particle in question has been "observed". Consequently,
the observational claims in question will thus have to be dismissed as
overstatements. On a general note, this demonstrates that the empirical support
for the Standard Model of particle physics is significantly less than hitherto
thought.
