Why doesn't pdg baryon list show quark compositions?

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Discussion Overview

The discussion centers around the absence of quark compositions and electrical charges in the Particle Data Group (PDG) baryon list, particularly regarding the Roper resonance. Participants explore the reasons for this omission and the context in which quark content is typically provided.

Discussion Character

  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant questions why the PDG baryon list does not include all variations of Roper resonances with different quark compositions despite having the same mass.
  • Another participant suggests that the quark content is usually provided or should be clear from context, prompting a clarification about what a "Roper resonance" is.
  • Several participants point out that while the quark content is available on the PDGLive website, it is not included in the printed PDF booklets, leading to confusion.
  • It is noted that the quark content is listed in the headings of sections in the PDG Booklet, which some participants find to be less accessible for non-professionals.
  • One participant argues that the primary purpose of the PDG Review is for professional physicists, implying that it may not cater to the needs of a broader audience.
  • Another participant emphasizes that professional particle physicists are expected to infer quark compositions from the naming conventions used in the listings.

Areas of Agreement / Disagreement

Participants express differing views on the accessibility of quark composition information in the PDG resources. While some believe the information is adequately provided for professionals, others feel it is not user-friendly for those less familiar with the field.

Contextual Notes

There is a mention of the specific section headings in the PDG Booklet where quark content is listed, which may not be immediately apparent to all users. Additionally, the discussion highlights the reliance on naming conventions to convey quark compositions, which may not be clear to everyone.

Garlic
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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?
 
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Usually the quark content is given, or should be clear from the context. Example. What is a "roper resonance"?
 
The quark content is given there, right above the large bold N(1440).
 
I was looking in the pdf booklet for nucleon-nucleon resonances. Here is a screenshot of it:
Roper.png

Okay, it seems that they don't write quark compositions only in pdf booklets.
 
Ah, hmm. pdgLive has it, and I rarely use the printed version.
 
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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.
 
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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.
 
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Vanadium 50 said:
It seems a bit unfair to complain

I wasn't complaining, I just couldn't understand why the list diddn't show quark compositions.
 
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Because professional particle physicists know the quark composition from the name.
 
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