Electromagne,c  Field  Genera,on  Using  a  Mul,phase  Transport  Model  in  Heavy-­‐Ion  

Collisions      

 2015  REU  Presenta0on    Presenter:    Tianen  Chen  

Mentor:    Dr.  Ko      

Quark Gluon Plasma (QGP)

• All matter was in the QGP for the first 10-6 seconds of the universe’s origin

• Created at high temperatures and energy densities

Heavy Ion Collisions

• Used to recreate the QGP

•  Relativistic Heavy Ion Collider (RHIC)

•  Large Hadron Collider (LHC) •  Forms “fireball” which is Quark-Gluon plasma.

A Multiphase Transport Model ●  AMPT is a Monte-Carlo Transport

system for Heavy-Ion Collisions at relativistic energies

●  Created to study QGP and collisions at RHIC and LHC.

●  Initial conditions come from HIJING, parton scattering from Zhang’s Parton Cascade (ZPC), and a Relativistic Transport Model(ART) for Hadronic scatterings.

Initial Calculations

Electromagnetic Field Calculation

b/2

RELATIVISTIC

NONRELATIVISTIC

Model behavior Bx By

Spatial Distributions

From  top  to  bo@om  and  leA  to  right,  these  are  the  spa,al  distribu,ons  of  the  electromagne,c  field  at  b=10fm  for  Ex,  Ey,  Bx,,  and  By,  respec,vely.  Note  that  the  average  is  not  the  absolute  value.  The  unit  of  E  and  B  in  this  case  is  mπ2.  

Ex Ey

Bx By

Time Evolution

Time  evolu,on  of  electromagne,c  fields  at  impact  parameter  b=10fm  for  gold  collisions  at  s1/2=200  GeV.  

Time  and  Strength  of  Magne,c  in  Y  direc,on  as  func,on  of  Energy  

By τ

s1/2

Time Evolution of Varying Cross Sections

Conclusions  

•  Conductivity of QGP is not constant, it is a function of ω and p.

Acknowledgments

•  Yifeng Sun

• Dr. Che-Ming Ko