Speaker
Dr
Yukinao Akamatsu
(Nagoya University)
Description
We propose a novel relation between the low-mass enhancement of dielectrons observed at PHENIX and transport coefficients of QGP such as the charge diffusion constant D and the relaxation time \tau. The observed low-mass enhancement sets a lower-bound on the diffusion constant, D > 2/T, with T being temperature.
To reach this lower bound, we start with the second-order relativistic
dissipative hydrodynamics by Israel and Stewart. The linearized hydrodynamic equation in external electromagnetic field gives a spectral function which is parametrized by D and \tau. Combining the spectral function with the full 3D hydrodynamic evolution, theoretical dielectron spectra and the experimental data are compared.
Detailed analysis shows that the low-mass dilepton enhancement originates mainly from the high-temperature QGP phase where there is a large electric charge fluctuation as obtained from lattice QCD simulations.
Primary author
Dr
Yukinao Akamatsu
(Nagoya University)
Co-authors
Prof.
Hideki Hamagaki
(University of Tokyo)
Prof.
Tetsufumi Hirano
(Sophia University)
Prof.
Tetsuo Hatsuda
(University of Tokyo)
