Theory parameter definitions
Table describing the variables used to specify theory choices in nnpdf. Here they are shown
directly as the fields of the runcards in theory_cards.
The Type column refers directly to data type of the field.
Field/key |
Type |
Description |
Comments |
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|---|---|---|---|---|---|---|---|---|---|
ID |
Integer |
TheoryID |
Theory enumerating ID |
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PTO |
Integer |
pQCD order |
(0/1/2 = LO/NLO/NNLO) |
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FNS |
Text |
Flavour Number Scheme |
e.g FONLL-A/B/C, ZM-VFNS or FFNS |
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IC |
Integer |
Intrinsic charm switch |
Boolean |
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ModEv |
Text |
DGLAP solution mode |
EXA/EXP/TRN |
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XIR |
Real |
\(\xi_R\) |
\(\mu_R/Q\) |
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XIF |
Real |
\(\xi_F\) |
\(\mu_F/Q\) |
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QED |
Integer |
QED switch |
Boolean |
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Q0 |
Real |
\(Q_0\) |
FK Table initial scale |
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mc |
Real |
\(c\) quark mass \(M_c/m_c(Q_{mc})\) |
Units: GeV |
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Qmc |
Real |
\(Q_{mc}\) |
\(c\) reference scale (GeV) |
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kcThr |
Real |
\(c\) production threshold ratio |
Ratio to \(m_c\) |
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mb |
Real |
\(b\) quark mass \(M_b/m_b(Q_{mb})\) |
Units: GeV |
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Qmb |
Real |
\(Q_{mb}\) |
\(b\) reference scale (GeV) |
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kbThr |
Real |
\(b\) production threshold ratio |
Ratio to \(m_b\) |
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mt |
Real |
\(t\) quark mass \(M_t/m_t(Q_{mt})\) |
Units: GeV |
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Qmt |
Real |
\(Q_{mt}\) |
\(t\) reference scale (GeV) |
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ktThr |
Real |
\(t\) production threshold ratio |
Ratio to \(m_t\) |
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CKM |
Text |
CKM matrix elements |
Unpacked 3X3 matrix |
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MZ |
Real |
\(M_Z\) |
\(Z\) mass (GeV) |
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MW |
Real |
\(M_W\) |
\(W\) mass (GeV) |
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GF |
Real |
\(G_F\) |
Fermi coupling constant |
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SIN2TW |
Real |
\(\sin^2\theta_W\) |
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TMC |
Integer |
Target mass corrections |
Boolean |
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MP |
Real |
\(M_P\) Proton mass |
Units: GeV |
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Comments |
Text |
General comments |
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alphas |
Real |
Strong coupling |
Format: \(\alpha_s(Q_{\textrm{ref}})\) |
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alphaqed |
Real |
QED coupling |
Format: \(\alpha_{QED}(Q_{\textrm{qedref}})\) |
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Qref |
Real |
\(Q_{\textrm{ref}}\) |
Reference scale for \(\alpha_S\) and \(\alpha_{\rm EW}\) in GeV |
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XIA |
Real |
\(\xi_A\) |
\(\mu_A/Q\) |
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NfFF |
Integer |
Number of flavours in the FFNS |
3/4/5/6 |
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nfref |
Integer |
\(n_f^{(\textrm{ref})}\) |
Number of active flavours at \(Q_{\textrm{ref}}\) |
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MaxNfPdf |
Integer |
\(n_f^{\textrm{max}}\) |
Used by pineko and the photon module to define the thresholds |
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nf0 |
Integer |
\(n_f^{(0)}\) |
Number of active flavours at \(Q_0\) |
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HQ |
Text |
HQ mass treatment |
POLE/MSBAR |
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IterEv |
Integer |
iterations for the evolution of the PDF |
Defaults to 60 when ModEv = EXA |
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ModSV |
Text |
Scale variation scheme |
expanded/exponentiated |
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DAMP |
Integer |
FONLL damping factor switch |
Boolean |
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DAMPPOWERc |
Integer |
Damping power for charm in FONLL |
needed when DAMP and FONLL are used |
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DAMPPOWERb |
Integer |
Damping power for bottom in FONLL |
needed when DAMP and FONLL are used |
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n3lo_ad_variation |
List |
IHOU variation of the N3LO anomalous dimensions |
Order is (gg |
gq |
qg |
nsp |
nsm |
nsv) |
|
with values 0 or 1 for FHMRUVV |
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n3lo_cf_variation |
List |
IHOU variations of the N3LO massive DIS coefficient functions |
Values are -1 |
0 |
1 |
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use_fhmruvv |
Integer |
use N3LO anomalous dimensions by FHMRUVV group |
Boolean |
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MaxNfAs |
Integer |
\(n^{(\alpha_s)}_{f \textrm{max}}\) |
Max active flavours in \(\alpha_s\) |
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SxRes |
Integer |
small-\(x\) resummation switch |
Boolean |
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SxOrd |
Text |
small-\(x\) pt switch |
(‘LL’, ‘NLL’, ‘NLL’) |
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EScaleVar |
Integer |
Switch for DGLAP scale variation |
Boolean |
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Qedref |
Real |
\(Q_{\textrm{qedref}}\) |
QED reference scale (GeV) |
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global_nx |
Integer |
Global x-grid precision |
Default (0) uses set-by-set precision |