Quantum numbers of a field acquiring vacuum expectation value

krishna mohan
Messages
114
Reaction score
0
Why should symmetries require a field that acquires vacuum expectation value to have the same quantum numbers as the vacuum? Please give me a reference also..if possible...
 
Physics news on Phys.org
If the vacuum (without the v.e.v. of the field) has certain symmetries dictated be observation, such as local Lorentz invariance and lack of electric charge, then the presence of the field v.e.v. should not ruin these properties. Otherwise you wouldn't have demanded those symmetries of the original vacuum. That's why condensations of neutral scalars and neutral, Lorentz-scalar groupings of fermions are allowed in the Standard Model.
 
javierR said:
That's why condensations of neutral scalars and neutral, Lorentz-scalar groupings of fermions are allowed in the Standard Model.

So how does one explain the vector meson?

Scalar mesons, such as the pion, are condensations of a colorless, Lorentz-invariant, quark/antiquark composite fields.

If there is a similar condensation (i.e., symmetry-breaking) that leads to a vector meson, then Lorentz-invariance would be broken.

So it seems that only scalar mesons should exist, and vector mesons violate Lorentz invariance because they would spontaneously break it?
 

Thread 'Toponium Discovered'

Toponium is a hadron which is the bound state of a valance top quark and a valance antitop quark. Oversimplified presentations often state that top quarks don't form hadrons, because they decay to bottom quarks extremely rapidly after they are created, leaving no time to form a hadron. And, the vast majority of the time, this is true. But, the lifetime of a top quark is only an average lifetime. Sometimes it decays faster and sometimes it decays slower. In the highly improbable case that...
View full post »

Thread 'Dirac-Delta from Normalization of Continuous Eigenfunctions'

I'm following this paper by Kitaev on SL(2,R) representations and I'm having a problem in the normalization of the continuous eigenfunctions (eqs. (67)-(70)), which satisfy \langle f_s | f_{s'} \rangle = \int_{0}^{1} \frac{2}{(1-u)^2} f_s(u)^* f_{s'}(u) \, du. \tag{67} The singular contribution of the integral arises at the endpoint u=1 of the integral, and in the limit u \to 1, the function f_s(u) takes on the form f_s(u) \approx a_s (1-u)^{1/2 + i s} + a_s^* (1-u)^{1/2 - i s}. \tag{70}...
View full post »

Similar threads

A Higgs particle and non-zero expected value in vacuum
Replies
3
Views
2K
A QFT with vanishing vacuum expectation value and perturbation theory
Replies
3
Views
2K
B Are real theories undiscoverable from effective field theories?
Replies
4
Views
2K
A Vacuum Transitions and Lorentz Symmetry Breaking
Replies
8
Views
2K
I New muon g-2 calculation consistent with experiment
Replies
0
Views
3K
A Breaking of a local symmetry is impossible, so what about global symmetry....
Replies
4
Views
3K
Classical and quantum electromagnetic field
Replies
2
Views
2K
A Higgs Expectation Value with Classical vs Quantum Potential
Replies
1
Views
2K
A Eigenstates of the Klein Gordon Field Operator
Replies
8
Views
277
A Importance of Densities in QFT
Replies
1
Views
2K

Hot Threads

Recent Insights

Back
Top