Helicity Definition and 62 Threads

What is the difference between chirality and helicity? I know, that helicity shows the handedness of the particle. For example, we have a right-handed electron if its spin is aligned in the direction of its propagation. The concept of chirality is a bit similar to that of helicity, but something...

Please look at the attach file. If we take case a) it proves the C and P are independly violated (neutrinos are left handed) The component of spin along the direction of motion is: -1 for the photon (bosons can have spin + or - 1) -1/2 for the neutrino (fermions can have spin + or -...

Ahoy maties, I understand that spin 'direction' relates to helicity, bosons have integral spin (-1, 0, 1, 2, etc) and that photons and Z-bosons are unique in that they are 'their own antiparticles'. With this context, I have 2 question strings (so I don't have to post multiple times)...

In relativistic quantum field theory the Dirac spinors can be chosen to be eigenstates of the helicity operator \vec{\Sigma}\cdot \vec{p} /|\vec{p}|. I want to show that \vec{\Sigma}\cdot \vec{a} commutes with the Dirac Hamiltonian only if \vec{a}\propto \vec{p}. As usual I'm using Einstein...

I have a proton and an antiproton scattering, via a pion exchange. The matrix element has the form: M=g*(\bar{u}_{1}\gamma ^{5}u_{2})\frac {1} {q^2-m^2}( \bar{v}_{1}\gamma ^{5}v_2) Wher g is my coupling constant, and q the 4-momentum of the pion. The problem is that when I compute the...

Does someone know what the measured probability of finding a right handed electron in the beta decay is?

When it was in the news about neutrinos having mass, I wondered what that meant about left-handed only-ness. You could catch up to one and pass it, or slow one down. More recently, I read that the helicity of the neutrino is invariant but the chirality can still change. What is the...

i am encoutering a problem i use helicity method to caculate six photon amplitude in scalar QED but i don't know explicit form of wave fuction QED . And i need a book with title " R. Gastmans, Ubiquitous photon: Helicity method for QED and QCD" where can i find it? thank you

It is quite difficult to understand, can someone explain what is helicity?

Hi, got an exam tomorrow for particle physics and need a question answered concerning helicity. How would it be possible to determine if a photon had a non-zero rest mass, based on measured helicity values? Thanks Ray

Who is the person that started the concept of magnetic helicity? Is it Gauss? Is it Woltjer? I was trying to obtain a copy of Woltjer's paper of 1958 Proc. Natl Acad. Sci. USA 44 480. Can anybody help me get a copy of this paper? I did purchased a paper by Mitchell A. Berger called "Introduction...

It is well-known that using the Clebsch decomposition of a velocity field, the helicity contained in an any closed vortex tube is zero. Does the converse hold? That is, given zero helicity in any closed vortex tube, does this imply that the velocity field has a Clebsch decomposition?