Methods of $\widetilde{D}_{c\rightarrow h}$ estimation are specific for each parton energy model. Also several attempts were made to extract $\hat{q}$ using lattice QCD calculations [@majumder2013calculating; @Panero:2013pla]. The effects of the medium on particle production are usually quantified by the nuclear modification factor (${\mbox{$R_{AB}$}\xspace}$): $$R_{AB}^{\rm cent}({\mbox{$p_T$}\xspace}) = \frac{1}{T_{AB}^{\rm cent}}\frac{dN_{AB}^{\rm cent}/d{\mbox{$p_T$}\xspace}}{d\sigma_{pp}/d{\mbox{$p_T$}\xspace}},$$ where $dN_{AB}^{\rm cent}$ is the particle yield measured in A+B collisions for a given centrality class ($cent$), $d\sigma_{pp}$ is the cross section of the same particle measured in ${\mbox{$p$$+$$p$}\xspace}$ collisions at the same collision energy, $T_{AB}^{\rm cent}$ is the nuclear thickness function for the event class [@Miller:2007ri]. The energy loss of hard-scattered partons causes a reduction of from unity towards smaller values.

Measurement of $\pi^0$ meson production is particularly interesting, because $\pi^0$s are abundantly produced and their yields can be measured up to high $p_T$ with good particle identification, an excellent signal-to-background ratio ($S/B$), and relatively small uncertainties using the electromagnetic calorimeters (EMCal) of the PHENIX detector. The $\eta$ meson has four times heavier mass than $\pi^0$ and an about 50% strangeness content. Thus measurements of $\eta$ allow to study the dependence of jet quenching on the hadron mass and flavor content. Measurement of $\eta/\pi^0$ in ${\mbox{A$+$A}\xspace}$ gives an opportunity to 