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2023:groups:smhiggs:ggf-an3lo:start

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Impact of aN3LO PDFs on ggF PDF-TH uncertainty

Comments

Pavel: will it be possible to compare the MSHT and NNPDF NNLO and aN3LO luminosities with the |y_X | < 2.5 cut? This is most relevant for the measurements.


Settings

Energies: $\sqrt{s}= 7, 8, 13, \mathbf{13.6}, 14, 33, 100\ \mathrm{TeV}$

PDF Sets:

NNLO PDFs aN3LO PDFs
MSHT MSHT
NNPDF4.0 NNPDF4.0 (prelim)
PDF4LHC21

Coefficient Function: Always N3LO (even when using NNLO PDFs)

iHixs Runcard (defines defaults): run3.card log out

1. ggF Stacked Error Plots (iHixs)

Recreate plots similar to Fig. 2 in iHixs, showing only the uncertainties:

  • $\delta(PDF)$,
  • $\delta(PDF-TH)$,
  • $\delta(\mathrm{scale})$

or (for aN3LO PDFs):

  • $\delta(PDFincTH)$,
  • $\delta(\mathrm{scale})$.

We will omit uncertainties not relevant to the study (namely $\delta(EW)$, $\delta(\alpha_s), \delta(1/m_t), \delta(t,b,c)$. Note that we can get away with varying both muR & muF instead of only muR (as recommended by MSHT20 aN3LO) since the muF variation is anyway tiny. see e.g. Fig. 2 (top) in [https://arxiv.org/pdf/2209.06138.pdf].

2. Cross Section Tables

Main production code is iHixs (validated on HTL with ggH and n3loxs).

Produce tables with:

  • $\sigma$ (total cross section)
  • $\delta(\sigma)$ breakdown of the errors on the cross section (see Study 1 for details)

Comments made by observing preliminary results presented in the initial session: The aN3LO/NNLO k-factor for MSHT ~0.98 and for NNPDF looked ~1 (very preliminary). The NNPDF NNLO result is above the MSHT result and so at aN3LO we may see an even larger disagreement.

3. Gluon Lumi Comparison

Ratio plots for PDFs and Luminosities.

Order Sets
$xg(x)$ aN3LO/NNLO MSHT/MSHT
NNPDF/NNPDF
$\mathcal{L}_{gg}$ aN3LO/NNLO MSHT/MSHT
NNPDF/NNPDF
$\mathcal{L}_{gg}$ NNLO/NNLO MSHT/PDF4LHC
NNPDF/PDF4LHC

The luminosity plots should also be created with $|y_X| < 2.5$ to see the impact of the Higgs rapidity cut.

2023/groups/smhiggs/ggf-an3lo/start.1687092385.txt.gz · Last modified: 2023/06/18 14:46 by stephen.jones