Landau hydrodynamics reexamined

Abstract

We review the formulation of Landau hydrodynamics and find that the rapidity distribution of produced particles in the center-of-mass system should be more appropriately modified as dN/dy ∝ exp{ p y 2 b − y 2 }, where y b = ln{ √ sNN /mp} is the beam nucleon rapidity, instead of Lan-The modified distribution agrees better with experimental dN/dy data than the original Landau distribution and can be represented well by the Gaussian distribution, dN/dy(Gaussian) ∝ exp{−y 2 /2L}. Past successes of the Gaussian distribution in explaining experimental rapidity data can be understood, not because it is an approximation of the original Landau distribution, but because it is in fact a close representation of the modified distribution. Predictions for pp and AA collisions at LHC energies in Landau hydrodynamics are presented.

Thermohydrodynamics: Where Do We Stand?

“…This description was later improved by Hwa (1974) and Bjorken (1983) and very recently, re-examined thoroughly by C. Y. Wong (2008) specifically focused to account for the experimental data that is available from RHIC. The recent results obtained by this author are also quite interesting specially because the method itself is quite independent of the methods described in the previous paragraphs and quite free from the more complicated techniques of quantum field theory.…”

Momentum kick model description of the near-side ridge and jet quenching

“…Only the sum of the absorptive, collisional, and radiative contributions, leading to the total attenuation coefficient ζ, can be obtained by comparison with experimental jet quenching data [Eqs. (73) and (75)]. …”

“…As we will focus our attention in the mid-rapidity region where experimental data are available, Bjorken hydrodynamics [43] and Landau hydrodynamics [71,72] coincide [73,74] and we can use Bjorken hydrodynamics to describe the longitudinal expansion. For a hydrodynamical system undergoing Bjorken longitudinal expansion, the transverse expansion can be described by the hydrodynamical solution of Baym et al [75].…”

Nonextensive perfect hydrodynamics — a model of dissipative relativistic hydrodynamics?

“…Here we shall present its nonextensive relativistic version from the point of view of high energy collision physics [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The characteristic feature of such a processes is the production of a large number of secondaries (multiplicities at present approach ∼ 10 3 ).…”