Males are aggressive, not usually harmful
It is in the pigeon and the dove to chase the female quite aggressively to chase her to the nest when she is near to laying eggs. This is normally very harmless, even though it may look like bullying to you.
He will peck at the back of her head and her neck and chase her until she goes to the nest. It is all he can think of and will do so even she is trying to eat. Don't worry, this is normal behavior. If she is laying eggs, put them together and let nature take it's course.
I have raised thousands of pigeons over a nearly 50 year period and have never seen a male kill his mate. They may pluck a few feathers or even draw alittle blood but the intent is solely to drive her to the nest. It is called "driving the hen" and is perfectly normal.
The only time I've ever seen this behavior get out of control was when I was raising Gouldian Finches and I began supplementing with vitamin E. The males became so aggressive that they were injuring the hens and I've never used vitamin E since. They acted as if they had gone insane. The seed of a proper diet contains all the nutrients that they need.
In times of stress or illness, vitamins may help but 90% of the time they are not needed. The only reason that I mention this is I began to wonder if you were giving vitamins to your birds. It's the only thing I've ever observed that actually seemed to goof up their normal behavior.
Bill