A process for producing polyethylene comprises polymerizing ethylene or copolymerizing {HEAD ~ ethylene} with other α olefin in {TAIL ~ the presence} of a catalyst system obtained by bringing the following components to in contact with one another: 
A process for producing polyethylene comprises polymerizing ethylene or copolymerizing { HEAD ~ ethylene } with other α olefin in { TAIL ~ the presence } of a catalyst system obtained by bringing the following components to in contact with one another :
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH