Okay, so I'm your manager and you come to me with the following:
"A female coworker and I were in some part of the building nobody else
was in. She was drunk but I didn't touch her or offend her. She
slapped me!"
So.. what were the two of you doing in this isolated part of the building? Why was one of you (just one of you?) drunk at a time when it would be the company's business to care? More to the point, why did you feel it was important to point out that you "didn't touch her?" If some crazy lady in the street attacked me, I wouldn't tell the cop I didn't touch or offend her. I'd just tell him she attacked me.
What happened here exactly? You were standing around in a broom closet by yourself doing nothing (model employee) and Suzy from accounting walked in, slammed 10 shots of tequila and then slapped you? You don't think management is going to want perhaps a little bit more detail than that? And will that detail paint your actions as an employee in a good light?
And why am I, your manager, supposed to be anything but pissed at you right now for coming to me with this complete and obvious BS? Drunks don't slap people. Angry drunks slap people who through interacting with them, made them angry. So yes, you did offend her somehow. After all there was nobody else there to offend her so what I want to know, is what you want me to do about this problem other than decide both of you were engaged in highly unprofessional behavior and verify that by getting Suzy's side of the story before tossing one but more likely both of you out on your asses before one or both of you decide it's the company's fault for not protecting the two of you from each other.
Unless of course the real story is just that you made a highly inappropriate and unwelcome advance on somebody at the company Christmas party, she got angry, and you're out for revenge for the slap. Then I'm just going to point out that you're a complete jackass in the most professional terms possible, and put a coded sticky note up reminding me to find a good excuse to fire you before the next company party because harassment suits bother me a lot more than you getting insult and assault twisted.
If the story really is more like this:
"I was just dropping off my TPS reports in the back room at 10:00 a.m.
Suzy tumbled out of the broom closet with a half empty bottle of
vodka, said something to me in slurred drunken speech and then just up
and slapped me!"
Then yes, you will see me suppress a laugh, because it's just patently absurd, and absurd is funny, but Suzy's days are numbered if you told me right away because it's not hard to tell if somebody is drunk on the job and no, I can't have drunk employees, especially ones that randomly pimp-slap people for no reason whatsoever. That's just two great reasons to fire somebody that go great together.
But neither version of this story is really that simple, is it? Or you would have told somebody about it right away. And there'd be a lot more details in the question. If you're not sure having all the facts of this incident laid out in front of a manager is going to advance your career at this place of employment, I'd let this one go and hope that Suzy does too. Maybe make a learning experience out of it by really soul-searching on what it was you did that could have pissed her off if she isn't just one of those very rare crazy completely irrational drunks. But if you think really, really hard about it, you might find that the one that's owed an apology is not you. And maybe it's not even her either. This looks to me like there were bad mistakes made on all sides. When that happens everybody is probably better off if nobody asks for justice.