Anisotropic distribution of nucleon participating in elliptical flow

Using the isospin dependent quantum molecular dynamics model, we study the effect of charge asymmetry and isospin dependent cross-section on $\frac{dN}{d(<Cos2\varphi >)}$ and $\frac{dN}{p_{t}d{p}_t}$. Simulations have been carried out for the reactions of ${}^{124}{X}_m{+}^{124}{X}_m$, where m = (47, 50 and 59) and ${}^{40}{S}_{16}{+}^{40}{S}_{16}$. Our study shows that these parameters depend strongly on the isospin of cross-section and charge asymmetry. The distribution of nucleons and fragments is not symmetric around the beam axis.