Suggestions for the Research of Particle Elliptic Flow and Higher Harmonics.pdfVIP

Suggestions for the Research of Particle Elliptic Flow and Higher Harmonics 1,2,3 ∗ 1 1 1 1 2 Ben-Hao Sa , Bao-Guo Dong , Yu-Liang Yan , Xiao-Mei Li , Hai-Liang Ma , and Dai-Mei Zhou 1 China Institute of Atomic Energy, P. O. Box 275 (18), Beijing, 102413 China 2 Institute of Particle Physics, Huazhong Normal University, Wuhan, 430079 China 3 CCAST (World Lab.), P. O. Box 8730 Beijing, 100080 China We give a transparent theoretical derivation for the elliptic flow and higher harmonics in the Fourier expansion of particle azimuthal distribution in momentum phase space starting from in- variant particle multiplicity distribution. It turned out that the harmonics (vn ) here should be an average of the particle corresponding operators first over particles in an event and then over events rather than “an average over all particles in all events”. In addition, the importance of completely considering the Fourier expansion coefficient in quantitative investigation of particle anisopropic azimuthal distribution is discussed by a partial mode (harmonic) analysis method. A method of the 8 0 calculation of vn followed by the partial mode analysis is proposed. 0 PACS numbers: 25.75.Dw, 24.85.+p 2 r Elliptic flow (v ) and higher harmonics (v , n=3, 4, The invariant particle multiplicity distribution can be p 2 n A ...) as Fourier expansion