Can transport peak explain the low-mass enhancement of dileptons at RHIC?

May 27, 2011, 7:10 PM
20m
Salon Haendel AB (Imperial Palace)

Salon Haendel AB

Imperial Palace

Allée Impérial 74000 Annecy, France Tél. : +33 4 50 09 30 00
Parallel Electromagnetic probes Electromagnetic probes

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)

Presentation materials