Trying my best- in NY it is called child abuse and CPS must be called if a parent hits other than the following way: They may hit with an open hand (rather than a fist), with nothing in their hand (no belt, book ect), and AS LONG AS NO MARK IS LEFT.
Other than that, pure and simple child abuse. Even by a parent, let alone a teacher.
Quick question- anyone out there who is a social worker, teacher, OT, PT, ect- they are required by law (and halacha) to report them to CPS. Abuse is abuse and there is no excuse for that.