I'm looking for the most damaging weapon (meaning does the most damage to HP on a successful hit) that can be wielded in one hand. I am looking for an answer for both magical and mundane weapons. The only stipulations I have are that it must lack the two-handed property and must be found in one of the sourcebooks on D&D Beyond that isn't listed as an adventure. The ability modifier doesn't matter because I will be overriding that with my CHA mod anyway.
For mundane weapons the best I've found is a rapier or other weapon with equivalent damage (1d8) but I'm not sure if there's another, more damaging one. Also, the lance does not count because the only way to wield it one handed is to be mounted.
My intent is to have a character (hexblade warlock X / two weapon fighter 2) wielding the weapons. The mundane weapon is for the levels before I can easily get magic items and so I can conjure at least one to be my pact weapon for Pact of the Blade.