Dynamics Evolution Equations And Higher Order Calculation At Small X

On the basis of the "Big Bang" theory, The current generated in the universe comes from the Big Bang 13.7 billion years ago.during the big bang, Produced a extreme environment ,the environment has very high temperature and high densi-ty .In this environment,it formed a kind of new material.It is the popular mate-ria quark-gluon plasma (QGP) that we are researching now.During the relativistic heavy ion collision process,we can simulate the environment that similar to the big bang.The relativistic heavy ion collision is mainly to study the physical form of the high-temperature and high-density extreme condition.But in the research,we found that the existence time of the quark-gluon plasma is very short ,we can not direc-t measure it.Going through the continuous efforts to study,we found that we can through the observation of collision state at the end of the physical phenomenon to indirect response.Elliptic flow triangular flow and anisotropic flow are one of the physical phenome-na at the end of the collision that are easy to obvious. Anisotropic flow was born in the early of the heavy ion collisions,So they are sensitive on the evolution process of space and time,became an important observation.And the final state particles'distribution is asymmetry, the final state particles are generated by the collision.It can use Fourier expansion to show the distribution.Elliptic flow triangular flow are the the second and the third coefficient of the Fourier expansion.So the elliptic flow triangular flow and anisotropic flow's reearch has become an important content in the field of relativistic heavy ion collisions.In this article,We use AMPT model to simulate the relativistic heavy ion colli-sion process.Respectively,(?)= 200GeV Au-Au collisions and (?)=2.76TeV Pb-Pb collisions. According to the final state of the particle produced by the colli-sions can azimuth using Fourier expansion,we has studied the definition of anisotropic flow.We use the incident plane method and two particle correlation method to cal-culate the anisotropic flow,and compare these two methods.According to the result of data,We found that the elliptic flow is depend on the transverse momentum,but The triangular flow and anisotropic flow with the the growth of the order,the depen-dence of the transverse momentum becomes weakly.So in the research of the depen-dence of the transverse momentum of anisotropic flow,elliptic flow become the main observed quantity.For elliptic flow,when in the Small momentum area,the elliptical flow's quantitative value are rising with the increase of horizontal momentum. When the horizontal momentum is constant, the rising of the elliptic flow with the central degree's increase is non monotone.When the horizontal momentum and mass heart energy remains unchanged,the elliptical flow decreases with the increase of the par-ticle quality. .These conclusions will help to the understanding of the nature of the relativistic heavy ion collisions medium.