All Questions
Tagged with baryons quantum-field-theory
15 questions
2
votes
0
answers
147
views
Which force is responsible for $\Sigma$(1385) decay?
I was looking at the excited state of the $\Sigma^+$, the $\Sigma^{*+}(1385)$, on Wikipedia. I was wondering which forces are responsible for its two most dominant decays
$$ \Sigma^{*+}(1385) \to \...
- 814
0
votes
0
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130
views
Spinor index contractions for baryons
For an $SU(N)$ QCD with $N_f$ flavours one writes baryons as
\begin{equation}
B^{{a_1}…a_{{N}_f}}=\epsilon^{i_1…i_N}\psi_{i_1}^{a_1}… \psi_{i_N}^{a_{Ν_f}}
\end{equation}
by contracting the colour ...
- 163
4
votes
0
answers
256
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’t Hooft anomaly matching and massless baryons
In Lectures on Gauge Theory by David Tong there is statement (section 5.6.3 The Vafa-Witten-Weingarten Theorems), that:
To invoke the full power of ’t Hooft anomaly matching, we needed to assume that ...
- 5,737
7
votes
1
answer
166
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Baryons in flavor $SU(N)$ (in ChPT)
For flavor $SU(2)$ (Isospin) we have two $\frac{1}{2}^+$ baryons, the nucleons. For flavor $SU(3)$ we have the eight baryons in the octet. In a world with $N$ light quarks we would see a baryon ...
- 81
4
votes
0
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126
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Spin of skyrmion
Baryons can be considered as solitions in Skyrme model(See also this post.):
Such Lagrangian haven't any information about number of colors. Bosonic or fermionic nature of baryons depends on number ...
- 5,737
3
votes
1
answer
311
views
One-form current in 3d QED
3d QED in IR can be described in terms of dual scalar field $\varphi$ have trivially conserved current with two indices, associated with U(1) one-form symmetry:
$$
J_{\mu\nu} = \epsilon_{\mu\nu\rho}\...
- 5,737
1
vote
2
answers
147
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Holographic dual to baryon
Baryons can be effectively described at low energies as solitions in Skyrme model, that describe pions as NG bosons.
In Skyrme model exist current, that can be identified with baryon number current, ...
- 5,737
0
votes
1
answer
87
views
Nuclei violating B number
Within SM, it is know that baryon number is not preserved and changes as
$$
\Delta B = 3·\Delta n_{CS}, \quad n_{CS} \in \mathbb{Z}\ ({\rm Chern-Simons\ index\ for\ vacuum})
\tag1$$
Then, its ...
- 1,607
0
votes
0
answers
60
views
B violation and electric charge
Within SM you can prove that despite we have baryon number conservation respect to Noether theorem, at quantum level baryon (and lepton) number is violated as
$$
\Delta B = 3·\Delta n_{CS}, \quad n_{...
- 1,607
5
votes
0
answers
134
views
Number of baryons in the Skyrme model
In QCD, the Eightfold Way organizes the number of baryons with respect to their flavor and color quantum numbers: for three light $(u,d,s)$ quark constituents, a spin-(1/2) baryon octet and a spin-(3/...
- 1,803
11
votes
1
answer
2k
views
Why do we antisymmetrize the baryon's wavefunction but not the meson's?
A many-body wavefunction of identical fermions must be antisymmetrized because of fermionic statistics. We don’t antisymmetrize the meson wavefunction because it contains a quark and an antiquark, and ...
- 7,928
2
votes
1
answer
386
views
$\Omega^0_c \to \Sigma^+ K^-K^- \pi^+$ Feynman diagram
How can I work out the Feynman diagram for the decay process, $\Omega^0_c \to \Sigma^+ K^-K^- \pi^+$?
user147457
9
votes
1
answer
323
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How do topological excitations of the pion field carry a baryon number?
I have heard (numerous times) that topologically nontrivial pion field configurations carry baryon number. It's clear the the field configurations can carry a topological quantum number (the winding ...
Buzz♦
- 17.1k
3
votes
1
answer
130
views
Baryons annihilation
I was wondering if there is a way of calculate the annihilation cross section for two baryons, say $p\bar p\to\pi\pi$ or $p\bar p\to\gamma\gamma$. The problem here is that we cannot use the usual ...
1
vote
2
answers
431
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Why are the charge operator $Q$ and the baryon number operator $B$ unbounded?
A friend recommended me to read PCT, Spin and Statistics, and All That written by R. F. Streater and A. S. Wightman. In page 5 to 6, here's what the authors of this book have to say:
[...] In fact ...
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