Recent content by blankvin

Yes, that's it. See P&S, p.285-286: k is defined as a constant times n. This makes sense.Thanks, blankvin.

Thinking back to my complex analysis course, I think the bar `|' represents "such that", or "where". So, ∏n | kn0>0 can be read as "an infinite product over n, where kn0 is greater than zero". This also became a little more clear once I picked up Peskin and Schroeder, and looked at Ch9.2.

Hi, In my QFT course, the professor writes an infinite product like this: ∏n | k n0 > 0 ∫... My question is, what does the `|' in the subscript "n | k" representing? When I see `|', I think logical OR - obviously that is not it. Normally, if it's a sum over two indices, commas separate the...

I figured it out. Working out the S^{\mu}S^{\nu} terms lead to zero contribution to the amplitude. This blunder will be blamed on fatigue.blankvin

I know what the amplitude is. It is how to deal with the S^{\mu}S^{\nu} that I do not know.blankvin

Homework Statement I am working through an example in Chapter 6 of Quigg's Gauge Theories. I have it mostly figured out, with the exception of how to work out the S^{\mu}S^{\nu} term. All he writes is "...the term is impotent between massless spinors." Homework Equations I begin with: What...

I was considering the ultra-relatistic regime (E>>m), so abandoned the mass term in my calculation. Using the normalization constant ##\sqrt{E+m}## fixed my problem.Cheers, blankvin.

In Mark Thomson's Modern Particle Physics, Problem 6.7, I am wondering how we obtain: 2(ms, 0, 0, 0) and -2(ms, 0, 0, 0) for the RL and LR helicities (likewise for the muon) in the electron currents using helicity combinations. My solutions for the other helicities (RR, LL) work out, but I am...

I am trying to figure out when electrons are subject to an Aharonov-Bohm apparatus (the pick up a phase of +/- e(magnetic_flux)/(h_bar), how the interference fringes are shifted. I know de Broglie wavelength is given by lambda = h/p and that the fringe spacing without the vector potential is...

OK - I have I have it. A Lorentz transformation x^\mu \rightarrow {x'}^\mu = {\Lambda^\mu}_\nu x^\nu preserves the Minkowski metric \eta_{\mu \nu} , which means that \eta_{\mu \nu} x^\mu x^\nu = \eta_{\mu \nu} {x'}^\mu {x'}^\nu \hspace{3pt} \forall \hspace{3pt} x. Therefore...

{M^1}_1 Then for basis vectors, x_\mu {M^\mu}_\nu x^\nu = {M^\mu}_\nu ?

Would a "clever" choice be to multiply both sides on the right by x_\nu x_\mu? That is, multiplying both sides on the left by the inverses of x^\mu and x^\nu?

Hi, Can someone explain the difference between, say, \Lambda_\nu^\mu, {\Lambda_\nu}^\mu and {\Lambda^\mu}_\nu (i.e. the positioning of the contravariant and covariant indices)? I have found...

Thank you for the quick reply. Can you give me an example in this context or further explanation of what an infinitesimal Lorentz transformation is? Also, the unprimed to primed transformation is given. How do you go the other way? Is it correct to say that since \eta_{\mu \nu} x ^\mu...

I am attempting to read my first book in QFT, and got stuck. A Lorentz transformation that preserves the Minkowski metric \eta_{\mu \nu} is given by x^{\mu} \rightarrow {x'}^{\mu} = {\Lambda}^\mu_\nu x^\nu . This means \eta_{\mu \nu} x^\mu x^\nu = \eta_{\mu \nu}x'^\mu x'^\nu for all x...