Question
Answer the following about ways to simplify notation in quantum field theory, for 10 points each.
[10e] These diagrams, which represent particle interactions, are used to compactly express the expansion of S-matrix elements.
ANSWER: Feynman (“FINE-mun”) diagrams [or Stueckelberg diagrams]
[10m] Slash notation is used to express the contraction of a covariant quantity with these four matrices, which are used to form the spinor (“SPIN-or”) representation of the Clifford algebra.
ANSWER: gamma matrices [or Dirac matrices]
[10h] Freeman Dyson introduced this operation often used in the interaction picture. It precedes an exponential term in Dyson’s formula.
ANSWER: time-ordering operation [accept time-ordered product; prompt on path-ordering or path-ordered or T; reject “time evolution (operator)”]
<Physics>
Summary
| 2024 ACF Nationals | 2024-04-21 | Y | 24 | 16.25 | 92% | 54% | 17% |
Data
| Berkeley A | NYU | 10 | 10 | 0 | 20 |
| Chicago C | Berkeley B | 10 | 0 | 0 | 10 |
| Brown | Toronto A | 10 | 10 | 0 | 20 |
| Chicago A | Columbia A | 10 | 10 | 10 | 30 |
| Duke | Columbia B | 10 | 0 | 0 | 10 |
| Chicago B | Cornell A | 10 | 10 | 10 | 30 |
| Toronto B | Florida | 0 | 0 | 0 | 0 |
| Illinois | Yale A | 10 | 10 | 0 | 20 |
| Minnesota A | Indiana | 10 | 10 | 0 | 20 |
| Michigan | Iowa State | 10 | 0 | 0 | 10 |
| Chicago D | Kentucky | 10 | 0 | 0 | 10 |
| Maryland | Johns Hopkins | 10 | 10 | 0 | 20 |
| Cornell B | McGill | 10 | 10 | 0 | 20 |
| North Carolina B | Minnesota B | 10 | 10 | 10 | 30 |
| North Carolina A | Waterloo | 10 | 10 | 10 | 30 |
| Georgia Tech | Northwestern | 10 | 0 | 0 | 10 |
| Arizona State | Penn | 10 | 0 | 0 | 10 |
| WUSTL A | Purdue | 10 | 10 | 0 | 20 |
| Rutgers | Yale B | 10 | 0 | 0 | 10 |
| Stanford | Texas | 10 | 10 | 0 | 20 |
| Truman State | Harvard | 10 | 0 | 0 | 10 |
| South Carolina | Vanderbilt | 0 | 0 | 0 | 0 |
| Virginia | Ottawa | 10 | 10 | 0 | 20 |
| Claremont Colleges | WUSTL B | 10 | 0 | 0 | 10 |