What is more similar to particle physics, nuclear physics or condensed matter theory? After I complete my undergraduate studies, I am planning on applying for a Ph.D. in particle physics. I would like to complete my final project in this field, but everyone at my university works in either nuclear or condensed matter physics. Which of these two fields would be more useful to a future Ph.D. applicant in particle physics? Nuclear physics seems to be very similar, but condensed matter has the same formalism (e.g., QFT). Any input would be greatly appreciated.
 A: It depends greatly upon whether or not you are doing experimental or theoretical research. As Luc J. Bourhis mentioned, experimental nuclear physics is very similar to experimental particle physics. Nuclear physics wants to study specific properties of atomic nuclei--particle physics wants to use similar techniques to study more fundamental components of matter. Experimentally, one could think of particle physics as nuclear physics at higher energies. See Cern's ISOLDE and 
Brookhaven National Lab's experimental group website for more on the similarities between experimental particle and nuclear physics.
If you want to go with theory, I would suggest you go into condensed matter. Many of the tools now used in particle physics were used in condensed matter. For example, the Higgs mechanism has its origins in superconductivity. Feynman diagrams are used extensively in condensed matter to describe the microscopic interactions of quasiparticles near the Fermi surface. As well, one of the big tools in theoretical condensed matter is the AdS/CFT correspondence, which is a correspondence between a spacetime of negative cosmological constant and a conformally invariant quantum field theory. This correspondence, originally used in string theory, might help explain a phase of metal known as a strange metal. Therefore, it would seem that an undergrad degree in one of the mathematical subfields of theoretical condensed matter physics would be greatly beneficial to a Ph.D. in particle physics.
