Theory parameter definitions

Table describing the variables used to specify theory choices in nnpdf. Here they are shown directly as the fields of the theory.db lookup table. The Type column refers directly to the sqlite3 data type of the field.

Field/key

Type

Description

Comments

ID

Integer

TheoryID

Theory enumerating ID

PTO

Integer

pQCD order

(0/1/2 = LO/NLO/NNLO)

FNS

Text

Flavour Number Scheme

e.g FONLL-A/B/C, ZM-VFNS or FFNS

DAMP

Integer

FONLL damping factor switch

Boolean

IC

Integer

Intrinsic charm switch

Boolean

ModEv

Text

DGLAP solution mode

EXA/EXP/TRN

XIR

Real

\(\xi_R\)

\(\mu_R/Q\)

XIF

Real

\(\xi_F\)

\(\mu_F/Q\)

NfFF

Integer

Number of flavours in the FFNS

3/4/5/6

MaxNfAs

Integer

\(n^{(\alpha_s)}_{f \textrm{max}}\)

Max active flavours in \(\alpha_s\)

MaxNfPdf

Integer

\(n^{(PDF)}_{f \textrm{max}}\)

Max active flavours in PDFs

Q0

Real

\(Q_0\)

FK Table initial scale

alphas

Real

Strong coupling

Format: \(\alpha_s(Q_{\textrm{ref}})\)

Qref

Real

\(Q_{\textrm{ref}}\)

Reference scale for \(\alpha_S\) in GeV

QED

Integer

QED switch

Boolean

alphaqed

Real

QED coupling

Format: \(\alpha_{QED}(Q_{\textrm{qedref}})\)

Qedref

Real

\(Q_{\textrm{qedref}}\)

QED reference scale (GeV)

SxRes

Integer

small-\(x\) resummation switch

Boolean

SxOrd

Text

small-\(x\) pt switch

(‘LL’, ‘NLL’, ‘NLL’)

HQ

Text

HQ mass treatment

POLE/MSBAR

mc

Real

\(c\) quark mass \(M_c/m_c(Q_{mc})\)

Units: GeV

Qmc

Real

\(Q_{mc}\)

\(c\) reference scale (GeV)

kcThr

Real

\(c\) production threshold ratio

Ratio to \(m_c\)

mb

Real

\(b\) quark mass \(M_b/m_b(Q_{mb})\)

Units: GeV

Qmb

Real

\(Q_{mb}\)

\(b\) reference scale (GeV)

kbThr

Real

\(b\) production threshold ratio

Ratio to \(m_b\)

mt

Real

\(t\) quark mass \(M_t/m_t(Q_{mt})\)

Units: GeV

Qmt

Real

\(Q_{mt}\)

\(t\) reference scale (GeV)

ktThr

Real

\(t\) production threshold ratio

Ratio to \(m_t\)

CKM

Text

CKM matrix elements

Unpacked 3X3 matrix

MZ

Real

\(M_Z\)

\(Z\) mass (GeV)

MW

Real

\(M_W\)

\(W\) mass (GeV)

GF

Real

\(G_F\)

Fermi coupling constant

SIN2TW

Real

\(\sin^2\theta_W\)

TMC

Integer

Target mass corrections

Boolean

MP

Real

\(M_P\) Proton mass

Units: GeV

global_nx

Integer

Global x-grid precision

Default (0) uses set-by-set precision

EScaleVar

Real

Switch for DGLAP scale variation

Boolean

Comments

Text

General comments