Can the Palestinian Authority Negotiate Peace With Israel?

Today's question is whether the Palestinian Authority can negotiate peace with Israel. I'm not asking whether it is likely to happen when Abbas sits down with Netanyahu, I'm asking a more basic question -- are they the ones who should be sitting down? What is being negotiated and who has the right to do it?

If they are negotiating peace, then it seems like the people who should be at the table are the combatants. The Palestinian Authority is not at war with Israel, Hamas is. So, why negotiate with the PA? Making peace wihtout addressing the combatants would be like apologizing to Hanno because I hit Kerry in the nose.

On the other hand, if they are negotiating and end to the occupation and establishing borders for a new Palestinian nation, it would seem that you would need to sit down with the closest thing to a provisional government. The PA is that, sort of, although they lost the election in Gaza to Hamas. Having Hamas at the table would in one way make any agreement that emerged more legitimate, but it would also practically guarantee that no agreement would emerge. You would be buying legitimacy at the price of sabotaging the process.

On the third hand, if what is being negotiated is something that will come back to the people for ratification in a referendum of some sort, then it wouldn't matter who did the negotiating since they really are not being given the power to speak for the people.

Should the PA be considered the voice for "the Palestinians"? What exactly are they negotiating? Or is there an exactly here?