Number-of-constituent-quark scaling of elliptic flow:a quantitative study

The number-of-constituent-quark(NCQ)scaling behavior of the elliptic flow of identified particles produced in A+A collisions is studied quantitatively using an empirical function that fits the experimental v_(2) data available from the RHIC and LHC.The most common approach for NCQ scaling involves(1)doing a scaling of the experimental v_(2) data of an identified particle with its NCQ,(2)doing the same to its transverse momentum or energy,then(3)combining all the scaled data and identifying the NCQ behavior by intuitively looking(since the measured experimental data are discrete).We define two variables(d_(1),d_(2))to describe NCQ scaling quantitatively and simultaneously,and identify the approximate region where the NCQ scaling holds.This approach could be applied to study NCQ or other scaling phenomena in future experiments.

System scan of the multiplicity correlation between forward and backward rapidities in relativistic heavy-ion collisions using a multi-phase transport model

A systematic study on forward–backward(FB)multiplicity correlations from large systems to small ones through a multi-phase transport model(AMPT)has been performed and the phenomenon that correlation strength increases with centrality can be explained by taking the distribution of events as the superposition of a series of Gaussian distributions.It is also found that correlations in the η−ϕ plane can imply the shape of the event.Furthermore,long-range correlations originate from the fluctuations associated with the source information.FB correlations allow us to decouple long-range correlations from short-range correlations,and may provide a chance to investigate the α-clustering structure in initial colliding light nuclei as well.It seems the tetrahedron ^(16)O+^(16)O collision gives a more uniform and symmetrical fireball,that emits the final particles more isotropically or independently in the longitudinal direction,indicating that the forward-backward multiplicity correlation could be used to identify the pattern of α-clustered ^(16)O in future experiments.