New answers tagged

1

Penrose's Non-linear graviton construction works for a complex Riemannian Manifold (dim - 4). Here, one deforms a twistor space (or its dual space) to produce anti self dual (resp. self dual) parts of Weyl curvature which satisfy source free graviton equation. However, we live in a real Lorentzian manifold so both left handed and right handed gravitons are ...


3

Here's the distinction: Parity converts left-handed chiral spinors to right-handed chiral spinors, and conversely: $\psi_L\leftrightarrow \psi_R$. Chiral symmetry means symmetry under $\psi_L\to e^{i\phi_L}\psi_L$ and $\psi_R\to e^{i\phi_R}\psi_R$, where the phase-factors $e^{i\phi_L}$ and $e^{i\phi_R}$ can be different. (It can also refer more ...


2

The first answer references the strong CP problem which is that there's a possible mechanism for breaking CP which QCD in nature appears not to make use of. To address the other part of the question, I want to explain why this has nothing to do with chirality as usually defined in the QCD context. Of course parity and chirality are very overloaded terms in ...


2

Chirality is related to parity, correct? It is a form of 'parity'? Chirality generators are odd under a parity transformation: A mirror reflection reverses chirality, left to right, and vice-versa. They are different operators which is why they have different names. A parity transformation is discrete, but a chiral transformation is continuous, effected by ...


1

In our mathematical description QCD could violate CP-symmetry due to its non-abelian nature, which introduces the CP-symmetry violating theta-term into the action. It does neither contribute to perturbation theory nor to the equations of motion because it is a total derivative. In a naive quantization in the Schrödinger picture it influences the energy ...


7

There are lots of questions on this site about chirality versus helicity, but you can clear them all up by just remembering that helicity is a property of particles (since it's defined in terms of a particle's momentum and spin), and chirality is a property of fields (since it's defined in terms of a field's Lorentz transformation properties). Fields are ...


0

Yes, antiparticle is still involved in left-handed chirality. The right-handed antiparticle that some books mention is actually helicity. I know many textbooks are WRONG by claiming that antiparticle is right-handed chirality. *** The weak interaction doesn't care about helicity, it just cares about chirality, and left-hand chirality is the one that involved ...


Top 50 recent answers are included