That's 'assault and battery'. When he touched you he committed battery. Contrary to popular belief, assault is not a physical attack - it's merely a verbal threat that makes you apprehend an attack. When he touches you, that is battery.
In England and Wales, battery is usually a summary offence, but if tried, it can be punishable with imprisonment for a term not exceeding six months, or a fine not exceeding level 5 (£5000) on the standard scale, or both. Of course, usually it doesn't work out anywhere near that nicely, and these idiots usually get off with a warning.