Azimuthal flow of decay photons in relativistic nuclear collisions

作者：Layek Biswanath^*; Chatterjee Rupa; Srivastava Dinesh K

来源：Physical Review C, 2006, 74(4): 044901.

DOI：10.1103/PhysRevC.74.044901

An overwhelming fraction of photons from relativistic heavy-ion collisions has its origin in the decay of pi(0) and eta mesons. We calculate the azimuthal asymmetry of the decay photons for several azimuthally asymmetric pion distributions. We find that the k(T) dependence of the elliptic flow parameter v(2) for the decay photons closely follows the elliptic flow parameter v(2)(pi 0) evaluated at p(T)approximate to k(T)+delta, where delta approximate to 0.1-0.2 GeV, for typical pion distributions measured in nucleus-nucleus collisions at relativistic energies. Similar results are obtained for photons from the 2-gamma decay of eta mesons. Assuming that the flow of pi(0) is similar to those for pi(+) and pi(-) for which independent measurements would be generally available, this ansatz can help in identifying additional sources for photons. Taken along with quark number scaling suggested by the recombination model, it may help to estimate v(2) of the parton distributions in terms of azimuthal asymmetry of the decay photons at large k(T).

• 出版日期2006-10