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#99 closed enhancement (fixed)
running alpha from LHAPDF
| Reported by: | Generic User (don't modify these fields) | Owned by: | support@sherpa-mc.de |
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| Priority: | minor | Milestone: | |
| Component: | Unknown | Version: | 1.2.2 |
| Keywords: | alphaS LHAPDF | Cc: | daniel.maitre@durham.ac.uk |
Description
It would be nice if there was the possibility to use the alpha_s that comes with the PDF when one uses the LHAPDF library. It is probably the most consistent thing to do since the PDF are fitted using that alpha_S. Attached is a plot of the ratio of the Sherpa alpha_s to the alpha_s from LHAPDF for CTEQ6L1. It seems clear that there is a difference in the treatment of the top threshold. At large scales it can have a sizable effect.
Attachments (1)
Change History (4)
Changed 14 years ago by
| Attachment: | Ratio2.png added |
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comment:1 Changed 14 years ago by
| Milestone: | → perfection |
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comment:2 Changed 13 years ago by
| Milestone: | rel-perfect → rel-1.3.0 |
|---|---|
| Resolution: | → fixed |
| Status: | new → closed |
This is included in trunk, use option USE_PDF_ALPHAS=1. Quark masses will have to be set consistently by hand. Note that this alpha_s does not have a top threshold.
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Ratio (alphas_Sherpa)/(alphas_LHAPDF) for CTEQ6L1