# A Why doesn't pdg baryon list show quark compositions?

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1. Jun 12, 2016

### Garlic

Why doesn't pdg baryons list show the quark compositions and electrical charges?
For example, there is only one roper resonance entry, but there are two roper resonances with different quark compositions (although they have the same mass), why not list all the variations?

2. Jun 12, 2016

### Staff: Mentor

Usually the quark content is given, or should be clear from the context. Example. What is a "roper resonance"?

3. Jun 12, 2016

### vanhees71

4. Jun 12, 2016

### Staff: Mentor

The quark content is given there, right above the large bold N(1440).

5. Jun 13, 2016

### Garlic

I was looking in the pdf booklet for nucleon-nucleon resonances. Here is a screenshot of it:

Okay, it seems that they don't write quark compositions only in pdf booklets.

6. Jun 13, 2016

### Staff: Mentor

Ah, hmm. pdgLive has it, and I rarely use the printed version.

7. Jun 13, 2016

### websterling

In the PDG Booklet (and also the Review) the quark content is listed in the heading for the section. The N BARYONS heading is about 3 pages before the N(1400) listing.

Similarly the quark content for say the $\Delta$ BARYONS is listed in that heading a couple of pages later.

8. Jun 13, 2016

Staff Emeritus
Garlic, the primary purpose of the Review of Particle Properties is not outreach. It may not be suited for what you want - but that's not its job. It seems a bit unfair to complain that a tool for professional particle physicists is not as helpful to people who are not professional particle physicists.

Also, the quark content is given at the top of the PDFLive page for the N(1440). It seems a bit unfair to complain that a tool for professional particle physicists has the information, but not where you looked for it.

Finally, Section 8, "Naming scheme for hadrons" explains how the N in N(1440) encodes the quark content. It's Rule 1 in Section 8.4.

9. Jun 14, 2016

### Garlic

I wasn't complaining, I just couldn't understand why the list diddn't show quark compositions.

10. Jun 14, 2016