The answer is obvious, but not easy when you are in love. When My ex cheated on me, I honestly saw no hope for us and didn't even try this, though I should have in order to expedite the process of getting over her. I just kept talking to her because it felt good, but I knew it would end. I was at least hoping that at some point she would be decent to me and give me a proper farewell if I kept talking to her, but she just wasn't a decent person. It just dragged it out.
In your situation, you may have hope. Either way, cut contact with her for a month, go on dates and keep the sex to a minimum (sexual chemistry should be evaluated when you meet these girls, but it shouldn't eclipse any opportunities to get to know these girls as people.) Meet girls with a clear and well defined list of personality traits that you look for in a partner. See how these girls stack up. Go at it with the objective of "seeing if she can be replaced." Remember, any experiences you had with her are independent from her and replaceable, you can have those same experiences, different ones, and better ones with anyone else. You need to see if SHE is replaceable.
After a month or two of this, you can re-initiate contact if you truly feel you want her back, and if you did it right and actually got some samples of whats out there, you will have a much more level head to successfully rebuild a brand new relationship with your ex from scratch. Remember, don't meet girls with the objective of getting her back, meet girls with the objective of seeing if you actually want her back. You have to not want her back before you can think straight enough to actually get her back.
In short, it isn't likely to happen because you have to no longer care if it happens before you can make it happen. By the time you are ready to create a new relationship with her successfully, you probably wont bother because not caring is a requirement for it to work.