You can use ItemLastPublishedDateCriteria
criteria to specify the last published date filter that you are looking for, for retrieving the pages that were published after specific date.
Given below is the sample code to achieve the same. Please note, code is not tested.
var itemTypeCriteria = new ItemTypeCriteria(64);
var lastPublishedCriteria = new ItemLastPublishedDateCriteria(<specify date>)
Criteria criteria = CriteriaFactory.And(itemTypeCriteria, lastPublishedCriteria);
var pages = new Query(criteria );