%0 Journal Article
%T Lectures on Landau Hydrodynamics
%A Wong
%A Cheuk-Yin
%J High Energy Physics - Phenomenology
%D 2008
%I 
%X Landau hydrodynamics is a plausible description for the evolution of the dense hot matter produced in high-energy heavy-ion collisions. We review the formulation of Landau hydrodynamics to pave the way for its application in high-energy heavy-ion collisions. It is found that Landau's rapidity distribution needs to be modified to provide a better quantitative description. In particular, the rapidity distribution in the center-of-mass system should be more appropriately given as dN/dy \exp{\sqrt{y_b^2-y^2}}, where y_b=\ln{\sqrt{s_NN}/m_p} is the beam nucleon rapidity, instead of Landau's original result of dN/dy({Landau}) \exp{\sqrt{L^2-y^2}} where L=\ln{\sqrt{s_NN}/2m_p}. The modified distribution is compared with the Landau distribution and experimental data. It is found that the modified distribution agrees better with experimental $dN/dy$ data than the Landau distribution and it differs only slightly from the Landau Gaussian distribution dN/dy(Landau-Gaussian) \exp{-y^2/2L}. Past successes of the Gaussian distribution in explaining experimental rapidity data arises, not because it is an approximation of the original Landau distribution, but because it is in fact a close representation of the modified distribution.
%U http://arxiv.org/abs/0809.0517