If a complex scalar (e.g. a complex Lagrangian) is invariant under a global SU(N) symmetry, the complex conjugate of this scalar is also invariant, right?
That is, the real and imaginary part of the complex scalar are both invariances with respect to the SU(N) independently.
I am not quite...
The phrase 'Coulomb branch' appeared several times in a paper on M-branes, but I don't know its meaning.
Is there anyone who explain it for me?
Thanks.
Thanks for your reply. However, I am not sure whether it's right.
Another answer, which may be wrong, is that in four dimensions the spinors are 4-dimensional, then one could obtain 4*8=32 for the N=8 case.
But what does it mean, and why Is it in accordance with the 32 real supercharges?
Provided that no particles have spins higher than 2, maximal supergravities are defined to be with supergravities with 32 supersymmetries.
Why is the N=8 supergravity in four dimensions called 'the maximal supergravity'? I am confused now...
Thanks.
Here I have some questions when reading a paper on supersymmetry. I am not familiar with those phrases below.
1, what is called 'rigid symmetry'?
2, does 'propagating degrees of freedom' mean degrees of freedom on shell?
3, when one says 'the gauge field are not dynamical', does it mean it...
Are there any books or papers which explain these notations like OSP(N|4), sl(m|n)? It seems they are all considered as superalgebras, but how is this kind notation generally defined?
By the way, I know for a 3-d superconformal field theory, OSP(8|4) means a SO(8) R-symmetry and a Sp(4)...
Do you think what happens when a electron comes to a proton then they combine a Hydrogen? According to the calculation of E-M potential, The binding energy is negative, which means it costs energy to separate them again.
I guess what you meant is that if the intermedia boson is massive, such as W-boson, then the related interaction should be short-ranged. For W,Z+,Z-, it is weak interaction.
Well~~why~~I am not sure. We can calculate the propogators in coordinate-space, and use the C-S equation to get the...
I am really sorry because I didn't make the question clear and said some silly words. To be honest, I was confused by those conceptions.
Ok, I just want to know why the positive W boson is so short-lived with a lifetime of about 3 × 10−25 s, which is almost the typical tme scale for a strong...
Really?
In my opinion, the poin decays to a quark, an anti-quark and a W boson first. Then the W boson decay into leptons via the weak interaction. But the annihilation of the left q and anti-q should be a strong interaction precess.
Is it true?
Thanks for all your replies.
I just thought that the lifetime of W boson, with the weak interaction decay, would be much larger, as the characteristic constant of weak interaction is much smaller that that of Strong interaction.
But the fact is just opposite. What is the right relationship of...
The positive W boson decays to a anti-muon and a muon neutrino, it should be a weak interaction.
And the positive Pion can decays to a anti-muon and a muon neutrino, too.
But the lifetimes of them are totally different, so why?
I know the positive Pion is composed of two quarks, but could you...