How is it possible to get into PhD in a different institute than Masters when publications take so long?
There are two ways to look at this question, both of which are answered in the comments. The first of which is just you asking, "I have submitted for publication, but they haven't been accepted yet." As Per Alexandersson said, make a list, write submitted, and if it's in mathematics, you can even link to Arxiv.

But addressing the implication of the question that it is required to have publications to matriculate, I'm not sure that's entirely accurate. Many Ph.D. Programs accept students directly out of their undergraduate degree, and so to expect them to have published research would be generally unfair. It makes more sense for Ph.D. programs to be looking for students who have the capability for research. This capability can be shown through projects that go beyond the scope of the classroom, research with professors that didn't necessarily result in publication, or as astronat mentioned in the comments, by strong references letters from supervisors, professors, etc.