All Questions
Tagged with quantum-chromodynamics symmetry-breaking
8
questions with no upvoted or accepted answers
3
votes
0
answers
267
views
Why is the chiral condensate a negative quantity?
The chiral condensate serves as an order parameter for the chiral phase transition. Thus, it is a finite quantity in one phase and vanishes in the other phase. It is given as a vacuum expectation ...
- 457
3
votes
0
answers
69
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Restoration of symmetry explicitly broken by anomaly
What is the meaning of the restoration at finite temperature of a symmetry that is "broken" by the presence of an anomaly. If the symmetry is not there why is it restored at finite ...
- 861
3
votes
0
answers
360
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Pion mass in theta vacuum
Does the mass of the charged pion depend on the QCD vacuum angle? I've seen it said---e.g., in these TASI lectures---that when the quark mass matrix is real and there is a nonzero QCD vacuum angle $\...
- 61
2
votes
0
answers
86
views
No global monopoles in QCD
If a global symmetry gets both spontaneously and explicitly broken, the explicit symmetry breaking pattern is crucial for understanding the formation of topological defects.
For example, in the axion ...
- 1,783
1
vote
0
answers
46
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Do hierarchical condensates yield instantaneous or sequential symmetry breaking?
I am wondering whether the formation of a hierarchical vacuum condensate yields an instantaneous or sequential symmetry breaking in a cosmological phase transition. Let me illustrate this question ...
- 1,783
1
vote
0
answers
195
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Why does the $U(2n)$ flavor symmetry break down to a $U(1)$ group and an $SU(2n)$ group?
I am studying quantum field theory using Srednicki's textbook. Problem 83.1 is:
Suppose that the color group is $G_C=SO(3)$ rather than $SU(3)$, and that each quark flavor is represented by a Dirac ...
- 1,653
1
vote
0
answers
410
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How to find the explicit value of the fermion vacuum expectation value?
In the derivation for Goldstone modes, a pdf I found online (scipp.ucsc.edu/~dine/ph222/goldstone_lecture.pdf) says it's believed the above-mentioned expectation value $\langle \bar{ \psi} \psi \...
- 737
0
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0
answers
76
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Are the arrangements of quarks in hadron ground-state wavefunctions rotationally symmetric?
The Hamiltonian of quantum chromodynamics (like the rest of the Standard Model) is rotationally symmetric. My question is whether these space symmetries are spontaneously broken in the ground state of ...
- 48.4k