All Questions
2
questions
0
votes
1
answer
180
views
Why does isospin symmetry survive chiral symmetry breaking?
In QCD there is a breaking of chiral symmetry such that, for the lightest quarks only, we have
$$\langle \overline{u} u \rangle = \langle \overline{d} d \rangle = \mathrm{const.}$$
where the constant ...
- 841
3
votes
1
answer
483
views
Relevance of the condensate $\langle 0 | \bar q q | 0 \rangle$ to SSB of chiral QCD symmetry
The QCD lagrangian with two massless flavours of quarks takes the form $$\mathcal L = \sum_{i=u,d} i \bar q_i \gamma_{\mu} D^{\mu} q_i.$$ Defining operators to project out the left and right handed ...
- 3,569