Here, my signal declaration:
void mySignal(MyClass *);
MyClass *myObject=new myClass();
You can connect a signal with as many slots as you want so you should make sure that none of those slots are able to do something you would not want them to do with your object:
constreference then, depending on your connection type, QT will pass the value of the object for you (see this for some details)
See also this question for some thoughts about passing pointers in signals.