Kinetic mass shifts of $\rho$(770) and $K^*$(892) in Au+Au reaction at $E_\mathrm{beam}=1.23~A$GeV

Abstract

We explore the properties of the last generation of $\rho$(770) and $K^*$(892) resonances created in Au+Au reactions at E$_\mathrm{lab}=1.23$~AGeV via the reconstruction in the hadronic channel using the UrQMD model. Such resonance studies allow to obtain detailed information on the emission source in such reactions in a complementary way to di-lepton or HBT studies. We observe a freeze-out hierarchy and predict mass shifts for the $\rho$(770) resonance ($\Delta m_\rho \approx -330$ MeV) and the $K^*$(892) resonance ($\Delta m_{K^*} \approx -30$ MeV). These mass shifts are related to the regeneration cycles of each resonance species and are of purely kinetic origin. Experimentally our predictions can be tested using the GSI-HADES experiment or the lowest RHIC-BES energy.