  Based on a newly proposed mirror-matter model of neutron-mirror neutron
($n-n'$) oscillations [Phys. Lett. B 797, 134921 (2019)], evolution and
nucleosynthesis in single stars under a new theory is presented. In the new
model, $n-n'$ oscillations are caused by a very small mass difference between
particles of the two sectors. The new theory with the new $n-n'$ model can
demonstrate the evolution in a much more convincing way than the conventional
belief. In particular, many observations in stars show strong support for the
new theory and the new $n-n'$ model. For example, progenitor mass limits and
structures for white dwarfs and neutron stars, two different types of core
collapse supernovae (II-P and II-L), synthesis of heavy elements, pulsating
phenomena in stars, etc, can all be easily and naturally explained under the
new theory.
