Polarization vector sums in QED - Physics Forums
Nov 9, 2018 · Thus you can change the polarization matrix according to (3) which corresponds to the radiation gauge of the free photon field to with an arbitrary vector field .
Matrix element squared for up + antidown -> photon + W
Jun 19, 2012 · When you sum over photon polarization vectors, some gauge vector, r, enters the calculation (see page 4). By making the following clever choice for the gauge vector: r = (0,1,i,0), a …
Interpretation of photons having zero spin • Physics Forums
Sep 16, 2017 · What is the interpretation of the fact that photons have spin zero? Does it has do to with the fact that their proper time variation is zero? Or let's go a bit deeper into the math. If it's possible to …
Understanding Spin-2 Bosons & Graviton Theory of Gravity
Mar 8, 2016 · So what you're saying is that in the case of an electromagnetic field, even though it's a Tensor field (just like gravity), and the carrier of the electromagnetic field is a spin-1 vector particle, …
Light polarization vs photons spin - Physics Forums
Nov 5, 2011 · A single photon can be in a mixed state. (5) For unpolarized light in particular, the idea that the density matrix implies that each photon has a definite polarization is incoherent. For …
Compton effect: how can it take place? - Physics Forums
May 11, 2017 · So, the incident photon interacts with the free (weakly bounded) electron in the Compton scattering and transfers partially momentum and energy to that particle, but it remains the same …
Can A White Photon Exist?not so easy to Answer - Physics Forums
Feb 7, 2005 · I read this question in a book. but i think a color of a photon is an expression of it's energy . the white light is consist of 7 colours ( 7 frequencies ) . and the photon can exist in one frequency …
QED replacing photon field with current in 3-point function
May 13, 2025 · The discussion centers on the all-orders proof of the equality ##Z_1=Z_2## in Quantum Electrodynamics (QED) using the Ward-Takahashi identity as presented in Schwartz's "Quantum …
Beam-splitter transformation matrix - Physics Forums
May 25, 2019 · The discussion revolves around the transformation matrix for a beam splitter, focusing on its properties, particularly the conditions for unitarity and energy conservation in the context of …
LS vs jj couplings and their selection rules - Physics Forums
Apr 3, 2019 · One participant questions the appropriate matrix element for jj coupling, suggesting it differs from the electric dipole matrix element used in LS coupling. Another participant emphasizes …