Speaker
Prof.
Ralf Rapp
(Texas A&M University)
Description
A relatively small spectral slope and large elliptic flow of direct photons
measured at RHIC and LHC has reignited the discussion of thermal photons as a
probe of the quark-gluon plasma (QGP). We present a systematic discussion of the
macro- and micro-physics that figures into calculating thermal emission spectra.
For the bulk medium we compare the temperature and flow evolution in fireball [1]
and hydrodynamic approaches [2], and study how different tunes of initial
conditions, compatible with bulk hadron observables, affect the photon spectra.
We deduce evidence for an enhancement of currently available hadronic and QGP
emission rates around Tc, and a potential suppression of early QGP radiation
(indicative for a gluon-rich early QGP). We then present an updated (more complete)
assessment of hadronic emission channels involving meson exchange reactions in
baryon-meson scattering which have not been considered thus far [3]. We also
investigate consequences for thermal dilepton v2.
[1] H. van Hees, C. Gale and R. Rapp, Phys. Rev. C 84 (2011) 054906
[2] H. van Hees, M. He and R. Rapp, in preparation.
[3] N. Holt and R. Rapp, work in progress.
| On behalf of collaboration: | None |
|---|
Primary author
Prof.
Ralf Rapp
(Texas A&M University)
Co-authors
Hendrik van Hees
(Goethe University Frankfurt)
Min He
(Nanjing University of Science and Technology)
