Perda de referência de um objeto Thread

public class StaticSync
{
    public static final Object s_lock = new Object();
    public static int s_counter=0;

    public static void main(String... args){
        new StaticSync().go();
    }
 
    public void go(){
        for(int iCounter=0; iCounter<50; iCounter++){

            Thread thread = new Thread(new Incrementer(new StaticSync()));
            thread.start();
        }
    }
}
 
class Incrementer implements Runnable
{
    StaticSync m_staticSync=null;
    public Incrementer(StaticSync staticSync_INP){
        m_staticSync = staticSync_INP;
    }
 
    public void run(){
        synchronized (m_staticSync.s_lock){
            m_staticSync.s_counter++;
            System.out.println(m_staticSync.s_counter);
        }
    }
}

.
.
.
  Thread thread = new Thread(new Incrementer(new StaticSync()));
  thread.start();
  thread = null;
}