  Using QCD sum rules and chiral SU(3) model, we investigate the effect of
temperature, density, strangeness fraction and isospin asymmetric parameter on
the shift in masses and decay constants of the pseudoscalar $D$ and $B$ meson
in hadronic medium, which consist of nucleons and hyperons. The in-medium
properties of $D$ and $B$ mesons within QCD sum rule approach depend upon the
quark and gluon condensates. In chiral SU(3) model, quark and gluon condensates
are introduced through the explicit symmetry breaking term and the trace
anomaly property of the QCD, respectively and are written in terms of scalar
fields $\sigma$, $\zeta$, $\delta$ and $\chi$. Hence, through medium
modification of $\sigma$, $\zeta$, $\delta$ and $\chi$ fields, we obtain the
medium modified masses and decay constants of $D$ and $B$ mesons. As an
application, using $^3 P_0$ model, we calculate the in-medium decay width of
the higher charmonium states $ \psi(3686)$, $\psi(3770)$ and $\chi(3556)$ to
the $D \bar{D}$ pairs, considering the in-medium mass of $D$ mesons. These
results may be important to understand the possible outcomes of high energy
physics experiments, e.g., CBM and PANDA at GSI, Germany.
