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8
votes
0answers
110 views

Probability of forming mesons vs baryons

When a heavy quark hadronizes it has some probability of forming a meson vs forming a baryon. I suspect there is a well known branching ratio for each type of hadron. Does anyone know what the ...
7
votes
2answers
96 views

How can $\Lambda^0$ and $\Sigma^0$ both have $uds$ quark content?

Title says it all: How can $\Lambda^0$ and $\Sigma^0$ both have $uds$ quark content? Doesn't this make them the same baryon?
7
votes
4answers
893 views

Baryon asymmetry

Baryon asymmetry refers to the observation that apparently there is matter in the Universe but not much antimatter. We don't see galaxies made of antimatter or observe gamma rays that would be ...
6
votes
4answers
986 views

If the quarks in a neutron are (up,down,down), why isn't it negatively charged?

If the quarks in a neutron are (up,down,down), why isn't it negatively charged? Excuse the silly question, just wondering.
6
votes
2answers
243 views

Why do quarks tend to bond in groups of three?

Why do quarks tend to bond in groups of three? I understand why they might in bond in groups of three to create a net charge of zero (i.e. neutrons), but I don't understand why they form protons and ...
6
votes
1answer
314 views

Has non-conservation of baryon number been observed?

CP violation (as I understand it) allows for non-conservation of baryon number, and thus can contribute (at least a little) to the baryon asymmetry in the universe today (far more matter than ...
5
votes
6answers
2k views

Is it possible to destroy proton in proton-proton collision?

Or in proton-electron collision. To destroy is to turn into other particles, not baryons. In context of the baryon asymmetry.
5
votes
0answers
139 views

Final-state baryons in $p \bar p$ collisions in Pythia

I'm trying to simulate inclusive $\chi_c$ production in $p \bar p$ collisions at very low energies (~ 5.5 GeV) using Pythia8 event generator. Leaving aside problems bounded with applicability of ...
4
votes
2answers
83 views

Do Baryons have Quantized Vibrational and Rotational States?

Given that baryons are not point particles but are composed of three quarks, are there quantized vibrational and rotational states analogous to those of molecules? If not why not, and if so are ...
4
votes
1answer
348 views

Does the Anti-Up, Anti-Strange, Anti-Strange Quark combination form a Baryon?

I was using this applet: http://www.lon-capa.org/~mmp/applist/q/q.htm And I saw that the up, strange, strange quark combination formed this Baryon: But the anti-up, anti-strange, anti-strange ...
4
votes
1answer
82 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 ...
4
votes
1answer
130 views

Baryonic Missing Mass

A recent article from a popular astronomy website tells of discovery of missing mass (not dark matter) that has puzzled astronomers for some time. Apparently, the discovery involves enhanced electron ...
3
votes
3answers
262 views

What barriers exist to prevent us from turning a baryon into a anti-baryon?

At present the only way we can produce anti-matter is through high powered collisions. New matter is created from the energy produced in these collisions and some of them are anti-matter particles ...
3
votes
1answer
74 views

How to calculate U-spin for baryons

I am trying to calculate U-spin for sigma baryons. I don't know why U-spin for $\Sigma^{+}$ and $\Sigma^{-}$ and $\Sigma^{*+}$ is 1/2, but for $\Sigma^{*-}$ is 3/2? I know that $\Sigma^{+}$ and ...
3
votes
3answers
697 views

Second baryon octet

Let's temporarily ignore spin. If 3 denotes the standard representation of SU(3), 1 the trivial rep, 8 the adjoint rep and 10 the symmetric cube then it's well-known that 3 x 3 x 3 = 1 + 8 + 8 + 10 ...
2
votes
4answers
481 views

Is it possible to split baryons and extract useable energy out of it?

Since baryons (e.g. protons, neutrons) are composite particles it should be possible to split them apart. If so, is it then possible to extract useable energy out of the splitting of baryons in ...
2
votes
1answer
736 views

How to calculate the density of relic neutrinos?

May be not neutrinos, but antineutrinos? Or both types? In the last case, why they didn't annihilate and what is the ratio of relic neutrinos to relic antineutrinos? Is that ratio somehow related to ...
2
votes
2answers
952 views

What is the correct term for the “polarity” of matter (matter vs. antimatter)? Are fractional polarities allowed?

What is the correct term for the "polarity" of matter (matter vs. antimatter)? Are neutral polarities allowed? (1,0,-1) Are fractional polarities allowed?
2
votes
1answer
265 views

Isospin of the neutral sigma baryon

I was typing up another answer on P.S.E. and I wanted to use the fact that the decay $$\Sigma^0\longrightarrow\Lambda^0+\gamma$$ does not occur strongly as an example of isospin conservation. But then ...
2
votes
1answer
63 views

Strange Matter and Stars

I am researching some stuff for a WorldBuilding.SE question, which asks if there is a true scientific method (not necessarily at our current technology level) to create a bomb capable of destroying a ...
1
vote
1answer
72 views

Baryon - Anti Baryon scattering

Is it possible, for a strong interaction of the above described type (baryon - anti baryon), to exist? $$B + \bar B \to \ldots $$ (Where $B$ is a generic baryon and $\bar B$ the anti-) Namely like ...
1
vote
3answers
90 views

Can a neutron decay to the gravitons?

Is it possible that a bunch of neutrons totally decay to the graviton? In other words, does the baryon number conserve in the quantum gravity interactions?
1
vote
1answer
111 views

Conservation of Baryon number for this proton decay

The conservation law requires that Baryon number be conserved; that is, the sum of the Baryon number before and after a reaction/ decay must always equal the sum of the Baryon number after the ...
1
vote
1answer
66 views

Angular momentum in baryon multiplets

In the Murray Gell-Mann model, particles are brought together as a function of their angular momentum. The classification diagrams can be seen as irreducible representations of $SU(3)$, following ...
1
vote
1answer
223 views

Parity of baryons. Why it is hard to find the parity determination of baryons?

I'd like to ask about parity of baryon. When I search a parity section of textbook, it only explain about parity of meson, not baryon. And I can't find experimental method for parity determination of ...
1
vote
0answers
40 views

Baryon effective Lagrangian

I'm trying to understand how to construct effective lagrangians for the hadrons. I understand the procedure for the mesons but I get stuck on baryons. In particular I don't understand how the baryons ...
1
vote
0answers
97 views

How to find Lepton Number? [closed]

is a Standard Model particle with (u, d, b) quark content. What are the electric charge, baryon number and lepton number of this particle? Is this the only particle expected to exist with this quark ...
1
vote
1answer
52 views

$\beta^+$ decay question

I read that all baryons apart from the proton itself decay into protons (why though?) and that mesons do not decay into protons due to having less mass than protons. Thus it makes sense for the ...
0
votes
2answers
116 views

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 ...
0
votes
2answers
370 views

What is the difference between leptons and baryons?

I am learning about the formation of the first atoms and, from what I am reading, before heavy particles, like neutrons and protons could form, there were already other types of particles, called ...
0
votes
1answer
40 views

What is the physical meaning of $\alpha$ in this disintegration problem?

I am taking a course where I have to solve the following problem related to the disintegration of a baryon in a proton and a pion $(\Lambda \to p^+ + \pi^-)$: Assume that a $\Lambda$ particle with ...
0
votes
1answer
218 views

Why is neutral sigma baryon more massive than lambda baryon?

Neutral sigma-star baryon, neutral sigma baryon and lambda baryon have masses 1387 MeV, 1192 MeV, 1116 MeV respectively, whereas each of these 3 particles are composed of 1 up, 1 down and 1 strange ...
0
votes
1answer
41 views

Is radiative decay the same the electromagnetic decay?

Question could be a duplicated of this one "Radiative" particle decay? An electromagnetic decay should be clearly one that involves at least a photon, either directly or producing a pair ...
0
votes
1answer
175 views

What is the baryonic mass distribution of the Milky Way

There are many, many studies of the Dark Matter halo around the Milky Way but I'm having trouble finding good raw data about visible matter. I'm investigating a MOND like model and would like some ...
0
votes
1answer
135 views

The counting of all possible baryons quark combinations

I would like to ask how do you count the number of possible quark combination that could possibly exist in a baryon. I know certain spin symmetry or orbital momentum symmetry have to be conserved. But ...
0
votes
0answers
16 views

Parent particles. Production modes of hyperon $\Lambda$

In the PDG are listed the decay modes of the known particles. I wonder if there exist lists with the production modes of particles. It is, lists with all the possible parent particles that decay into ...
0
votes
1answer
54 views

Isospin and Energy

I would to know if there is a correlation between isospin and energy. Consider for example the $\eta$ meson ($I =0$) and the pions($I=1$). The $\eta$ turns out to be much heavier then the pions ...