How may orientalism and prejudice contribute to hate crimes to the muslims and Arabs
This isn't science. It's social science or humanities or sociology.
Orientalism is the study of Asia -- but this term is rarely used among scholars who study prejudice and hate crimes. In my opinion, hate crimes against Muslims (note capitalization) and Arabs stem primarily from 9/11, other terrorist acts, and the continued conflicts in the Middle East between different Muslim groups.
You may want to check out this article.
http://en.wikipedia.org/wiki/Orientalism