Rotation and Turbulence in Peripheral Heavy Ion Collisions
Abstract
In our computational fluid dynamics (CFD) calculations the Kelvin-Helmholtz instability (KHI) starts to develop in peripheral collisions. At high energies the shear viscosity of the Quark Gluon Plasma (QGP) flow is becoming small and the Reynolds number will exceed one, thus turbulent phenomena may start to occur, which enhance the rotation effect in the expanding system. Due to the large initial state angular momentum, a new directed flow structure may appear that the anti-flow peak observed at high energies rotates forward, and directed flow will start to peak at positive rapidities at sufficiently high beam energy, i.e. on the same side where the projectile spectator residues arrive after the collision. This is because the initial angular momentum leads to a faster rotating initial system, and this rotation moves the dominant directed flow peak forward before the expansion from the pressure which would slow down the rotation. The observation of this peak is not easy because of the beam directed fluctuations of the initial state, and the directed flow is very sensitive and subject to significant perturbations from these random fluctuations. Thus we can study other effects, which are induced by the rotation of the expanding system. One is the polarization method: by calculating the thermal vorticity it turns out that the Lambda polarization can reach several percent in peripheral heavy ion collisions. The other is the Differential Hanbury Brown Twiss method, which is sensitive to rotation and it has advantages compared with the flow harmonics analysis.
Has parts
Paper I: L.P. Csernai, D.J. Wang, M. Bleicher and H. Stöcker. Vorticity in peripheral collisions at the FAIR and the NICA. Phys. Rev. C 90, 021904(R) (2014). The article is available at: http://hdl.handle.net/1956/9162.Paper II: L.P. Csernai, D.J. Wang and T. Csörgő. Rotation in an exact hydrodynamical model. Phys. Rev. C 90, 024901 (2014). The article is available at: http://hdl.handle.net/1956/9166.
Paper III: L.P. Csernai, S. Velle and D.J. Wang. New method to detect rotation in high-energy heavy-ion collisions. Phys. Rev. C 89, 034916 (2014). The article is available at: http://hdl.handle.net/1956/9167.
Paper IV: F. Becattini, L.P. Csernai and D.J. Wang. Λ polarization in peripheral heavy ion collisions. Phys. Rev. C 88, 034905 (2013). The article is available at: http://hdl.handle.net/1956/9168.
Paper V: D.J. Wang, Z. Néda and L.P. Csernai. Viscous potential flow analysis of peripheral heavy ion collisions. Phys. Rev. C 87, 024908 (2013). The article is available at: http://hdl.handle.net/1956/9169.
Paper VI: L.P. Csernai, V.K. Magas, D. J. Wang. Flow vorticity in peripheral high-energy heavy-ion collisions. Phys. Rev. C 87, 034906 (2013). The article is available at: http://hdl.handle.net/1956/9192.
Paper VII: D.J. Wang, L.P. Csernai, D. Strottman, Cs. Anderlik, Y. Cheng, D.M. Zhou, Y.L. Yan, X. Cai and B.H. Sa. QGP flow fluctuations and the characteristics of higher moments. Eur. Phys. J. A 48: 168 (2012). Full text not available in BORA due to publisher restrictions. The article is available at: http://dx.doi.org/10.1140/epja/i2012-12168-4.
Paper VIII: L.P. Csernai, S. Velle and D.J. Wang. Differential HBT method to analyze rotation in heavy-ion collisions. Nucl. Phys. A (2014). Full text not available in BORA due to publisher restrictions. The article is available at: http://dx.doi.org/10.1016/j.nuclphysa.2014.08.028.
Paper IX: L.P. Csernai and D.J. Wang. Rotation and turbulent instability in peripheral heavy ion collisions. EPJ Web of Conferences 71, 00029 (2014). The article is available at: http://hdl.handle.net/1956/9193.
Paper X: L.P. Csernai, F. Becattini and D.J. Wang. Turbulence, vorticity and Lambda polarization. Journal of Physics: Conference Series 509, 012054 (2014). The article is available at: http://hdl.handle.net/1956/9195.
Paper XI: L.P. Csernai, A.M. Skålvik, D.J. Wang,D. Strottman, C. Anderlik, Y. Cheng, Y.L. Yan and B.H. Sa. Directed flow from global symmetry and initial state fluctuations. Cent. Eur. J. Phys. 10, 1271-1273 (2012). Full text not available in BORA due to publisher restrictions. The article is available at: http://dx.doi.org/10.2478/s11534-012-0146-4.
Paper XII: L.P. Csernai, A.M. Skålvik, D.J. Wang, V.K. Magas, H. Stöcker, D.D. Strottman, Y. Cheng and Y.L. Yan. Flow components and initial state c.m. fluctuations. Acta Phys. Polonica B 43, 803 (2012). The article is available at: http://hdl.handle.net/1956/9196.