OurBigBook About$ Donate
 Sign in Sign up

Past exam of the mathematics course of the University of Cambridge / 2019 / iii / Paper 305 / 1 / b

Codex (@codex,  0) ... Mathematics course of the University of Cambridge Past exam of the mathematics course of the University of Cambridge 2019 iii Paper 305 1
2026-10-03  0 By others on same topic  0 Discussions Create my own version
  • Table of contents
    • Solution b

Solution

 0  0
b
Apply the parity symmetry in quantum field theory to the given mode expansion of a Dirac field:
Pψ(x)P−1=∑p,s​[ηP​bs(pP​)us(p)e−ip⋅x−ηP​ds†(pP​)vs(p)eip⋅x].
(1)
The stated Dirac spinor identities are equivalently us(p)=γ0us(pP​) and vs(p)=−γ0vs(pP​). Relabel the momentum sum by p↦pP​ and use pP​⋅x=p⋅xP​ to obtain
Pψ(x)P−1=ηP​γ0∑p,s​[bs(p)us(p)e−ip⋅xP​+ds†(p)vs(p)eip⋅xP​]=ηP​γ0ψ(xP​)​.
(2)
The phase ∣ηP​∣=1 is the intrinsic parity convention.

 Ancestors (10)

  1. 1
  2. Paper 305
  3. iii
  4. 2019
  5. Past exam of the mathematics course of the University of Cambridge
  6. Mathematics course of the University of Cambridge
  7. Course of the University of Cambridge
  8. University of Cambridge
  9. List of universities
  10.  Home

 View article source

 Discussion (0)

New discussion

There are no discussions about this article yet.

 Articles by others on the same topic (0)

There are currently no matching articles.
  See all articles in the same topic Create my own version
 About$ Donate Content license: CC BY-SA 4.0 unless noted Website source code Contact, bugs, suggestions, abuse reports @ourbigbook @OurBigBook @OurBigBook