When I see urls with one word (e.g., ux.stackexchange.com), I understand that this is the main page of the whole project, which explains the philosophy of whole project. It's like a "book cover." And bookmarking the page is equivalent to saving the project.
When I see a long url (e.g., ux.stackexchange.com/questions/97793/how-utm-long-urls-for-the-homepage-of-project-influence-on-user-experience) (imagine that I don't know about UTM keys) I subconsciously understand that it's an internal page. It's like "one of the pages in the book." And bookmarking the page is not saving the project; it's saving just one of the pages. In my mind the weight of this link is much smaller than one-word url.
Do you know any research/article on this topic? Are there any differences in human behaviour with single-word url and UTM'd url for a main website page? How many people will I lose (or not) if I use UTM for my domainname.com in different advertising posts?