What does a person have to do to get a doctorate in particle physics these days?
I ask because I am thinking about authorship. I still intend to write a follow-up post to an earlier one about a biology paper with over a thousand authors. Such large numbers of authors are increasingly becoming normal for papers of experimental particle physics.
My understanding of a doctorate is that it is supposed to represent the new contribution of a single individual to the scientific enterprise. I have never heard of any doctoral dissertation that was authored by multiple people.
If the papers in the field of particle physics are typically authored by huge collaborative teams, how can a grad student show that he or she has done independent research? Is that just not considered necessary for certain experimental fields in physics?
When does authorship stop meaning anything useful?