Unified description of Bjorken and Landau 1+1 hydrodynamics

TL;DR

This paper introduces a generalized analytic solution for (1+1) hydrodynamics that smoothly transitions between Bjorken's boost-invariant and Landau's non boost-invariant models, enhancing understanding of fluid dynamics in high-energy collisions.

Contribution

A new one-parameter family of solutions interpolates between Bjorken and Landau hydrodynamics, broadening the theoretical framework for describing relativistic fluid flows.

Findings

Derived explicit rapidity distributions for various freeze-out conditions.

Compared new solutions with original Bjorken and Landau models, showing their relation.

Provided insights into the proper-time scale for fluid velocity approaches.

Abstract

We propose a generalization of the Bjorken in-out Ansatz for fluid trajectories which, when applied to the (1+1) hydrodynamic equations, generates a one-parameter family of analytic solutions interpolating between the boost-invariant Bjorken picture and the non boost-invariant one by Landau. This parameter characterises the proper-time scale when the fluid velocities approach the in-out Ansatz. We discuss the resulting rapidity distribution of entropy for various freeze-out conditions and compare it with the original Bjorken and Landau results.