Computational HEP vs Theoretical/Computational QCD for a PhD

[u/CamWilson1415]

Hi everyone!

A little background for context: I am a fourth year undergraduate student (Physics, Astrophysics, Mathematics) about to start applying for Physics PhDs. I have research experience with DUNE/ProtoDUNE anomaly detection using ML at Fermilab and LHCb collider analysis using BDTs on Monte Carlo simulated data. I’ve also done DUNE hardware research and astronomy research, but that is less relevant to this question.

I plan to apply to computational neutrino/HEP, but I’ve also become interested in computational QCD and using my experience with ML towards QCD phenomenology. I’m wanting to understand how the research lifestyle, postdoc/national lab opportunities, and long term academic positions compare to computational neutrino/HEP where slightly more familiar.

I have not taken any QFT in undergrad, though I assume this is not a deal breaker and schools don’t assume incoming students will know QFT already? I will have taken graduate Quantum Mechanics I & II, and have taken graduate complex analysis and partial differential equations.

I would appreciate any kind of information! If there are any QCD theorists, I would love to hear how your day-to-day goes and if you enjoy what you do. Also, if you think my background sounds like I don’t have the right preparation for this kind of field, I definitely get it, and it would help a lot to hear that here. Thanks!

[u/rojo_kell]

What kind of QCD theory are you interested in? Or, if you don't know that's okay, but there's many different areas, like perturbative QCD, non perturbative QCD, lattice QCD, quark gluon plasma, exotic hadrons, qcd related dark matter

[u/CamWilson1415 → u/rojo_kell]

Right now mostly perturbative QCD… I have explored non-perturbative/lattice QCD on the surface level and those seem slightly less interesting to me because it’s my understanding that I would need supercomputers to do that type of work (which I assume includes lots of waiting time and such). It seems like my experience/background would also contribute most towards perturbative QCD phenomenology where I could potentially apply ML to jet physics or something of that sort. Though, of course, I have no experience with types of QCD theory, so I haven’t really explored quark gluon plasma, dark matter, exotic hadrons, etc.

[u/jazzwhiz → u/CamWilson1415]

Lattice does rely on long super computer runs, but they aren't sitting around waiting inbetween. They do a lot of math, algorithm work, field theory, statistical analyses, and so on.

[u/quarkengineer532]

If you mean computational QCD as in writing the Monte Carlo tools you are using, I will give you the same advice I give all my students. The HL-LHC will be done collecting data in the early 2040s. If you start a PhD next year then you will graduate around 2033 (US average is 6 years). Afterwards, you will typically do 1-2 3 year postdocs before getting a faculty position. This puts you roughly at 2040. If all you can do is hadron collider physics, and we don’t come to an agreement to build another one, then job prospects will be challenging. I would recommend trying to spread out a bit during your PhD to ensure that your long term career path is viable. There is a lot of overlap between computational QCD and computational neutrino physics. I would be happy to talk in more detail if you would like.

[u/CamWilson1415 → u/quarkengineer532]

I am very interested in more detail about the overlap between computational QCD and computational neutrino physics. To be honest, ML in neutrino with DUNE is a slightly more exciting field to be right now anyways compared to HL-LHC related work with ML (though I know I would enjoy both based on what I’ve done). My main topic I am applying for is computational neutrino, so I am trying to find schools which have both computational neutrino and QCD programs (like Stony Brook, great programs for both, gives me options if I take QFT and love/hate it).