On Wednesday I delivered my second (and last) presentation for the so-called "Research Skills" course of the MSc. As I anticipated in my first talk, the subject was color-kinematics duality (or more commonly called BCJ duality in this case) at one loop in nonSUSY Yang-Mills; the title follows from the article it was based on:
Color-Kinematics Duality for Pure Yang-Mills and Gravity at One and Two Loops
Zvi Bern, Scott Davies, Tristan Dennen, Yu-tin Huang, Josh Nohle arXiv:1303.6605 [hep-th]
The article was submitted on 26 Mar 2013 and was last revised 14 Jan 2015, so it's almost fresh from the oven.
These are the slides of my talk:
I basically went through the article, even if not in detail (which I don't claim to fully understand) and just mentioned briefly the two-loop and gravity parts. It took me between around 24 (of 25) minutes to finish the presentation, so it was about right. The relevant minimum background to follow the slides or at least superficially read the article is of course QFT and a little QCD.
In the end I received two interesting questions: for the first I pointed out that the "Yang-Mills squared" prescription does not give pure gravity, as denoted in slide 16 with the state decomposition $\underbrace{(1/2,1/2)}_{\text{gluon}}\otimes
\underbrace{(1/2,1/2)}_{\text{gluon}}=
\underbrace{(1,1)}_{\text{graviton}}\oplus
\underbrace{(1,0)\oplus(0,1)}_{\text{anti-sym tensor}}\oplus\underbrace{(0,0)}_{\text{dilaton}}$. A nice account of this can be found in this presentation by Alexander Ochirov: "Pure gravity amplitudes via color-kinematics duality in the fundamental representation".
Excerpt from A. Ochirov's talk: www2.ph.ed.ac.uk/~aochirov/talks/Nordita2015.pdf
The second was concerned with how color-kinematics arise from a more fundamental -group theory- level. The answer is surely not trivial. The article I used references to this other paper:
which I haven't had the time to read in depth, but it certainly should shed some light into this question.
All this "QCD meets gravity" stuff seems really exciting and it seems to be quite active lately... if I pass my examinations with good marks and do a good job with my dissertation project, I might as well consider pursuing a PhD in a related topic :-)
No comments:
Post a Comment