Speaker
Description
Resonances are excellent probes to understand the properties and evolution of the
QCD medium created in relativistic heavy-ion collisions.
Because of their short lifetime, resonances decay inside the
fireball and their decay daughters interact with particles present in the
medium. If the decay daughters are re-scattered
by other hadrons present in the medium, the resonance signal cannot
be reconstructed. On the other hand, pseudo-elastic interactions
among the hadrons can regenerate resonances. The properties of resonances
such as mass, width and yield are decided by the interplay of these processes.
The centrality-dependent resonance to non-resonance ratio measured at top
RHIC and LHC energies already hints at the dominance of
re-scattering in the hadronic phase of the medium at these
energies. The elliptic flow parameter, $v_{2}$, has
been widely used as a tool for understanding the dynamics of the
system created in the early stages of a collision.
Comparison between $K^{*0}$ and $\phi$ is very promising, because the
lifetime of these examples differ by a factor of ten, and $K^{*0}$ is expected
to be affected more by the hadronic phase. Moreover, both offer the advantage
of being vector mesons with masses close to that of the proton.
We report the production of $K^{*0}$ and $\phi$ resonances
in Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7,
11.5, 14.5, 19.6, 27, 39 and 200 GeV using the STAR detector.
We present invariant mass peak position, width,
yield and elliptic flow of $K^{*0}$ and $\phi$ at these beam energies,
including tests of NCQ scaling. Comparing the relative yield of
resonances to non-resonances between RHIC and LHC energies will help us to understand the relative contributions from the hadronic phase at these energies.
| Preferred Track | Baryon-Rich QCD Matter and Astrophysics |
|---|---|
| Collaboration | STAR |
