Flow harmonics from self-consistent particlization of a viscous fluid
  The quantitative extraction of quark-gluon plasma (QGP) properties from heavy-ion data, such as its specific shear viscosity $\eta /s$, typically requires comparison to viscous hydrodynamic or "hybrid" hydrodynamics+transport simulations. In either case, one has to convert the fluid to hadrons, yet without additional theory input the conversion is ambiguous for dissipative fluids. Here, shear viscous phase-space corrections calculated using linearized transport theory are applied in Cooper-Frye freezeout to quantify the effects on anisotropic flow coefficients $v_n(p_T)$ at both RHIC and LHC energies. Expanding upon our previous flow harmonics studies [1,2], we calculate pion and proton $v_2(p_T)$, $v_4(p_T)$, and $v_6(p_T)$. Unlike in Ref. [1], we incorporate a hadron gas that is chemically frozen below a temperature of 175 MeV, and use hypersurfaces from realistic viscous hydrodynamic simulations. With additive quark model cross sections and relative phase-space corrections with $p^{3/2}$ momentum dependence, rather than the quadratic Grad form, we find at moderately high transverse momentum noticeably higher $v_4(p_T)$ and $v_6(p_T)$ for protons than for pions. In addition, the value of $\eta /s$ deduced from elliptic flow data differs by nearly 50\% from the value extracted using the naive "democratic Grad" form of freeze-out distributions. To facilitate the use of the self-consistent viscous corrections calculated here in hydrodynamic and hybrid calculations, we also present convenient parameterizations of the corrections for the various hadron species (cf. Table I). 
Zack Wolff and Denes Molnar
nucl-th