[G12] [EXTERNAL] Re: CLAS-g12 flux / normalization uncertainty

[Volker Crede]

This is what confuses me … I agree that 5.7% is a more reasonable flux uncertainty but this number seems to be based on the fluctuations of flux normalized omega yields. This is what you call normalization uncertainty.

And what is called normalization uncertainty in the table seems to be an average deviation of three different cross sections from published g11a results.

5.7% sounds like a good number for the flux / normalization uncertainty and I can back it up with a reference.

One other question: The referee is asking for a typical value of the CLAS missing-mass resolution referring to our missing pi(0) in the 3pi final state. Would you know where such a value may be quoted? Perhaps in an instrumental paper or a technical note?

Thank you for replying so quickly … I have not received the g12 email, perhaps it didn’t go through.

Cheers,

       Volker


On Sep 14, 2020, at 5:01 PM, Eugene Pasyuk <pasyuk at jlab.org<mailto:pasyuk at jlab.org>> wrote:

I think it must be a typo in the Table 27, it should be 5.7 rather than 1.7 for the flux uncertainty.
Normalization uncertainty is coming from run-to-run variation of the normalized yield. Flux uncertainty is global uncertainty of flux. As I recall it came from variation of tagging ratio from different normalization runs. It is a single scaling factor for the entire tagging range.

-Eugene

From: Volker Crede <vcrede at fsu.edu<mailto:vcrede at fsu.edu>>
Sent: Monday, September 14, 2020 16:40
To: g12 <g12 at jlab.org<mailto:g12 at jlab.org>>
Cc: Eugene Pasyuk <pasyuk at jlab.org<mailto:pasyuk at jlab.org>>
Subject: [EXTERNAL] CLAS-g12 flux / normalization uncertainty

Dear Colleagues,

I am currently working on the referee report for our g12 eta paper and I stumbled over the following issue. On Page 94 of our run-group note (CLAS-NOTE 2017-002), it says that we should stick to the currently quoted lower bound of the systematic uncertainty for the g12 normalization of 5.7%.

Later in Table 27, we quote a flux uncertainty of 1.7% and a normalization uncertainty of 1.8%

Can somebody clarify the situation?

1. Where does the flux uncertainty of 1.7% come from?

2. How is the flux uncertainty different from the normalization uncertainty?

3. What have others used or what will others use for these uncertainties in their papers?

Best wishes,

       Volker

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