The Pathfinder Magus has access to Arcana, one of which is the Accurate Strike:
Benefit: The magus can expend 2 points from his arcane pool as a swift action to resolve all of his melee weapon attacks until the end of his turn as melee touch attacks.
The primary advantage of this is that you use the touch AC of your opponent (bypassing armour, shield and natural armour bonuses).
Most melee touch attacks don't use a weapon, so there is no weapon enhancement bonus to add, but these are weapon attacks acting as melee touch attacks – are the enhancement bonuses of the weapon used added to the touch attack rolls?
Best Answer
Touch attacks are independent of what weapon you're using. It only affects the target's AC for the purpose of the attack. It's otherwise like a normal attack, so you get your attack bonuses.