  The planet's mass loss is important for the planet's formation and evolution.
The radius valley (RV) is believed to be triggered by evaporation-induced mass
loss. As an alternative mechanism for the RV, the mass loss of post-impact
planets is thoroughly investigated in this work. The impact energy is converted
to the planet's internal energy, enhancing its core energy and accelerating
mass loss and orbital migration. As the host star changes from K-type to
F-type, the planet's mass loss and orbital migration increase. When the initial
gas-to-core mass ratio (GCR) is small, the migration efficiency for planets
around K-type stars will increase, which helps to suppress mass loss and retain
the planet's mass and radius within a specific range. On the contrary, planets
around more massive F-type stars experience more substantial mass loss,
potentially leading to complete mass loss, and migrate to orbits with longer
periods. Our calculation shows that planets around different spectral types of
host stars give rise to an RV ranging from 1.3-2.0 $R_{\oplus}$, consistent
with the observed range of 1.3-2.6 $R_{\oplus}$. Despite the presence of
uncertain parameters, the planetesimal impact can promote the RV establishment
for planets around host stars of different spectral types.
