Open heavy favor mesons in hot asymmetric strange hadronic matter - a QCD sum rule approach

The masses of the pseudoscalar open charm ($D^\pm$,$D^0$,$\bar {D^0}$ and $D_s^\pm$) and open bottom ($B^\pm$,$B^0$,$\bar {B^0}$,$B_s^0$ and $\bar {B_s^0}$) mesons in hot asymmetric strange hadronic matter are studied within a QCD sum rule approach. These masses are computed using the medium modifications of the light quark condensates ($\langle{\bar{q_i}}{q_i}\rangle$, with $(q_i,i=1,2,3)\equiv(u,d,s)$), the gluon condensates and other operators upto mass dimension 5, calculated within a chiral SU(3) model. The light quark condensates are obtained from the medium modifications of the non-strange and strange scalar-isoscalar fields ($\sigma$ and $\zeta$), and the scalar-isovector field, $\delta$, whereas, the (scalar and twist-2) gluon condensates are computed from the in-medium value of the dilaton field, $\chi$, which is incorporated within the model to simulate broken scale invariance of QCD. The odd part of the spectral function leads to the particle-antiparticle mass splittings for the heavy flavor mesons. The antiparticles with non-strange quark (antiquark) constituents are observed to have larger mass shifts, as compared to their particle counterparts, both in nuclear and hyperonic matter. For the strange-charm (strange-bottom) mesons, the value of $\langle {s}^\dagger {s} \rangle$ dominates over the contributions from the other operators of the odd part of the spectral function. This is observed as opposite behaviour of the particle-antiparticle mass splittings with the mass of the particle to be larger (smaller) than the antiparticle mass in nuclear (hyperonic) matter. The density and isospin asymmetry effects are observed to be the dominant medium effects which might have observable consequences on the production of charmonia and open charm mesons, and, on the production ratios, $D^+/D^-$ and $D^0/\bar {D^0}$, in asymmetric heavy ion collisions in the CBM experiment at FAIR at the future facility at GSI.