Beyond Standard Model (I am mathematician, not physicist, so I don't know what to read in the physics literature, I don't know the journals, where are the survey, etc...). I read in standard newspapers, so not in scientific journals, that physicists in elementary particle physics were very worried about the future of this field of research because only machines having the size of our galaxy could help to choose among all possible extensions of the Standard Model. Is it serious ? To make this question a little bit more serious, do there exist papers -probably yes- giving a general picture (for a mathematician, not a physicist !) about the possible theories beyond the Standard Model.
 A: Yes, the point about (some) of the energy scales requiring "an accelerator the size of the galaxy" is serious. But only in certain cases, and assuming we stick with the same accelerator designs we currently use, it's possible we'll be able to increase the energy required here on Earth.
In addition, we already use astronomy to perform particle physics experiments. Remember the scare stories about the LHC "creating a black hole that would destroy Earth"? These weren't taken seriously in the physics community because collisions 10 to 1,000 times more energetic happen in the atmosphere every few minutes-to-days when cosmic rays impact.
We study particles (usually muons) from these collisions, neutrinos from the Sun and many other particles from astronomical events. It's likely that if beyond-standard-model particles exist, and are beyond the practicalities of human-made accelerators, then we'll eventually find them in high energy astronomical events.
Your first stop in researching beyond-standard-model particles should probably be supersymmetry (SUSY). Start with wikipedia and then take a look at arXiv.org for a vast range of papers.
