# Questions tagged [baryons]

Baryons are hadrons (particles composed of quarks) with an odd number, at least 3, of valence quarks. The term is also often used in astrophysics, e.g. "baryonic matter", with a much looser definition understood to mean any matter composed mostly of baryons, but which may also include leptons and other particles, often in opposition to "dark matter".

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### Finding $\Sigma$ wavefunctions from proton wavefunction. Any operator which can achieve this?

Knowing the isospin part of the wavefunction of the proton, it is possible to find that of the neutron by applying the isospin lowering operator $I_-$ which sits horizontally to the left of the proton ...
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### Why can't $\Sigma$ baryons decay strongly?

First of all, I must say this is a homework question. The complete question includes particles like $p$, $e^-$, $\Lambda$ and $\Omega$. It's pretty easy to understand why $\Omega$ and $\Lambda$ have ...
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### Why are Delta baryons called "Delta isobars"?

A lot of people seem to call the $\Delta$ baryon "Delta isobar", however there is no mention of "isobar" on its Wikipedia page. Am I missing something? Why do people use the term &...
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### Probabilities of $\Omega^-$ baryon decay

The $\Omega^-$-decay can occur in a few different ways. According to this document (page 3, $\Omega^−$ DECAY MODES), the three most probable decays are \begin{align} \Omega^- &\to \Lambda^0 + ...
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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 ...
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### Is it possible that rescuing the Idea of a Baryo/lepto-dynamic Field had some Relevance in the FermiLab Result?

We know that Fermilab, Brookhaven, and other laboratories have found discrepancies with the SM. One option that almost immediately comes to mind is that the so-far exact conservation law of baryon and ...
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### Baryon to photon ratio

In Dodelson's "Modern Cosmology", the current baryon-to-photon ratio is defined as $$\eta_b \equiv \dfrac{n_b}{n_\gamma} = 5.5 \times 10^{-10} \left(\dfrac{\Omega_b h^2}{0.020}\right).$$ I ...
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### What fraction of the mass of all baryonic matter are black holes?

Is there a calculation of how much of the mass of baryonic matter is black holes, including supermassive black holes in the center of galaxies?
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### Like quark baryons

Why aren't there particles like neutrons or protons but with 3 up or 3 down quarks, instead of 2 up/1 down or 2 down/1 up. Does there have to be 2 different types of quarks for the strong force to ...
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### How does the process $\bar{K}^0+p \to \Lambda^0+\pi^+$ work?

I was asked to find an energy for the $\bar{K}^0+p \to \Lambda^0+\pi^+$ interaction for an exercise and I got curious about how the Feynman diagram for this process would look like. In terms of quarks,...
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### Is the process $\pi^{-}+p^+\to\bar{n}+n+n$ allowed?

Is the process $\pi^{-}+p^+\to\bar{n}+n+n$ allowed? Is there any collision involving only the mesons and baryons that would produce antibaryons (along with other particles)?
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### What happens to extra-galactic rays when they arrive at the solar system?

Quazars send baryons from other galaxies towards us which are deflected from by the local magnetosphere. The early solar system probably picked up many millions of extragalactic cosmic rays for every ...
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### Is the baryon number consistent when it comes to annihilation?

I've previously asked a question on here about if it was possible to change the barion number by radioactive decay, for example positron emission, and the answer was of course no, as the baryon number ...
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### Could a Λ or Σ baryon be stable inside a nucleus?

A common "cartoon model" of a nucleus is that there are a set of bound energy levels for the protons and a similar set of bound energy levels for the neutrons. The existence of these energy ...
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### Can protons and neutrons be completely converted into Leptons?

In beta decay, a neutron releases an electron and turns into a proton. The inverse happens, though usually not naturally, in positron emission, where a proton emits a positron and becomes a neutron. ...
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### What is a "multicharge nuclei"?

When doing some reading on particle physics, I came across the concept of a "multicharge nuclei". A Google search of this phrase returns a number of research papers, but no definition for what a "...
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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, ...
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### Resourcs on learning about 2-body resources

As a part of my Particle Physics Course, I will need to give a talk on 2-body resonances - What are they? Some examples like 𝐽(Ψ), Z boson and significance of those discoveries. I am looking for ...
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### $\Sigma^0$ and $n$ decay

I was asked to show that in the baryon octet, the $\Sigma^0$ baryon is the only particle which decays electromagnetically. Since it is an electromagnetic decay, strangeness should be conserved but I ...
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### Quark Chirality Constraints in Nucleons

SW Engr here educating myself on particle physics, apologies in advance for any phrasing errors. I tried the google machine to no avail. Q: If only left handed matter fermions experience the weak ...
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Let's consider about the Baryon octet diagram. We can identify the isospin $I_3$ symmetry by noticing the mirror symmetry with respect to the $I_3$, i.e. x-axis. However, how can we expand this into $... 1 vote 2 answers 144 views ### Why aren't Delta and Omega particles stable? Not only are they not stable their half-life is in the nanoseconds. Why are they so different from protons? -1 votes 1 answer 52 views ### Why don't hadrons form from quarks of all the same charge? Why don't Hadrons ever form from quarks of all the same charge? For instance you never see 2 or 3 up quarks together with no down quarks or vice-versa. 0 votes 1 answer 42 views ### Quark Model Families I cannot understand what we mean when we say that we organise baryons and mesons in families. In other words, i have seen that a lot of books mention the baryon J=1/2 family. What do we mean by that? ... 0 votes 0 answers 28 views ### Quark Model Family I have studied the baryon J=1/2 family.i did the$(Y,I_3) $diagram and started from the highest weight$(\frac{1} {2} ,\frac{\sqrt{3} }{2}) $which is the proton and used the operators$I_{+-} \ \ U_{... 82 and 126 are magic numbers for nuclei, so $^{208}\mathrm{Pb}$ is doubly stable. So it seems to me like the hypernucleus $^{209}_{\Lambda^0}\mathrm{Pb}$ would be stable as well, because the \$\Lambda^...