part

description

lo/lord

${\sigma }_0$

virt

$\mathrm{\Delta }{\sigma }_1^v$

real

$\mathrm{\Delta }{\sigma }_1^r$

nlocoeff/totacoeff

$\mathrm{\Delta }{\sigma }_1$

nlo/tota

${\sigma }_0+\mathrm{\Delta }{\sigma }_1$. For photon processes that include fragmentation, nlo also includes the calculation of the fragmentation (frag) contributions.

frag

Processes 280, 285, 290, 295, 300-302, 305-307, 820-823 only, see sections 13.67, 13.72 and 13.73 below.

nlodk/todk

Processes 114, 161, 166, 171, 176, 181, 186, 141, 146, 149, 233, 238, 501, 511 only, see sections 13.39 and 13.41 below.

snloR

$\mathrm{\Delta }{\sigma }_1^{a,>}$

snloV

$\mathrm{\Delta }{\sigma }_1^{a,<}$

snlocoeff/scetnlocoeff

$\mathrm{\Delta }{\sigma }_1^a$

snlo/scetnlo

${\sigma }_0+\mathrm{\Delta }{\sigma }_1^a$

nnloVVcoeff

$\mathrm{\Delta }{\sigma }_2^{a,<}$

nnloRVcoeff

$\mathrm{\Delta }{\sigma }_2^{a,v>}$

nnloRRcoeff

$\mathrm{\Delta }{\sigma }_2^{a,r>}$

nnloVV

$\mathrm{\Delta }{\sigma }_1^{a,<}+\mathrm{\Delta }{\sigma }_2^{a,<}$

nnloRV

$\mathrm{\Delta }{\sigma }_1^{a,>}+\mathrm{\Delta }{\sigma }_2^{a,v>}$

nnloRR

$\mathrm{\Delta }{\sigma }_2^{a,r>}$

nnlocoeff

$\mathrm{\Delta }{\sigma }_2^a$

nnlo

${\sigma }_0+\mathrm{\Delta }{\sigma }_1+\mathrm{\Delta }{\sigma }_2^a$

part

description

resLO

NLL resummed and matched

resonlyLO

NLL resummed only

resonlyLOp

NLLp resummed only

resexpNLO

NNLL resummed expanded to NLO

resonlyNLO

NNLL resummed

resaboveNLO

fixed-order matching to NLO

resmatchcorrNLO

matching corrections at NLO

resonlyNLOp

NNLLp resummed

resexpNNLO

N${}^3$LL resummed expanded to NNLO

resonlyNNLO

N${}^3$LL resummed

resaboveNNLO

fixed-order matching to NLO

resmatchcorrNNLO

matching corrections at NLO

resLOp

NLLp resummed and matched

resNLO

NNLL resummed, matched to NLO

resNLOp

N${}^3$LL resummed, matched to NLO

resNNLO

N${}^3$LL resummed, matched to NNLO

resNNLOp

N${}^3$LLp resummed, matched to NNLO

resonlyNNLOp

N${}^3$LLp resummed

nproc

The process to be studied is given by choosing a process number, according to Tables in Section 4. $f(p_i)$ denotes a generic partonic jet. Processes denoted as “LO” may only be calculated in the Born approximation. For photon processes, “NLO+F” signifies that the calculation may be performed both at NLO and also including the effects of photon fragmentation and experimental isolation. In contrast, “NLO” for a process involving photons means that no fragmentation contributions are included and isolation is performed according to the procedure of Frixione [55].

part

The type of calculation to be performed. Possible values are given in Tables 6.1 and 6.2.

runstring

When MCFM is run, it will write output to several files. The label runstring will be included in the names of these files.

rundir

Directory for output and snapshot files

sqrts

Center of mass energy in GeV.

ih1, ih2

The identities of the incoming hadrons may be set with these parameters, allowing simulations for both $p\overline{p}$ (such as the Tevatron) and $\mathit{pp}$ (such as the LHC). Setting ih1 equal to $+1$ corresponds to a proton, whilst $-1$ corresponds to an anti-proton.

zerowidth

When set to .true. then all bosons are produced on-shell. This is appropriate for calculations of total cross-sections (such as when using removebr equal to .true., below). When interested in decay products of the bosons this should be set to .false..

removebr

When set to .true. the branching ratios are removed for unstable particles such as vector bosons or top quarks. See the process notes in Section 13, or the process web-pages accessed via the list of processes for further details.

ewcorr

Specifies whether or not to compute EW corrections for the process. Default is none. May be set to exact or sudakov for processes 31 (neutral-current DY), 157 (top-pair production) and 190 (di-jet production). For more details see section 5.3.

taucut

Optional. This sets the value of the jettiness variable ${\tau }_{\text{cut}}$, as a multiple of the invariant mass of the Born system, i.e.

This variable separates the resolved and unresolved regions in NNLO calculations that use zero-jettiness. The default value results in total inclusive cross sections with less than $1\%$ residual cutoff effects.

tcutarray

Optional. Array that specifies multiple taucut values that should be sampled on the fly in addition to the nominal taucut value. Both larger and smaller values than the nominal one can be specified, although uncertainties for smaller values will be large. We generally do not recommend smaller values than the nominal one chosen with taucut. Default values are chosen to be $2,4,8,20,40$ times the nominal choice of taucut.

dynamictau

Optional. If .false., the taucut value specified is not multiplied by the invariant mass of the Born system. Default is .true..

useqt

Flag to use $q_T$ slicing, rather than 0-jettiness, in the calculation of NNLO contributions. Default is .false.

useGLY

If .true., implement non-local $q_T$ subtraction using formulas from Gehrmann et al.(GLY) [56]. Default is .true. when useqt is enabled. If .false, implement non-local $q_T$ subtraction using formulas from Billis et al.(BEMT) [57].

qtcut

If useqt is enabled, the value of the slicing parameter, defined in the same way as taucut described above.

tauboost

When using 0-jettiness, perform the slicing cut in the centre-of-mass of the color singlet system. Default is .true.

incpowcorr

When using 0-jettiness, include leading power corrections in the below-cut calculation. Default is .false.

onlypowcorr

When using 0-jettiness, only compute the power corrections to the below-cut calculation. Default is .false.

usept

This flag has two separate uses. In a fixed-order sliciing calculation, e.g. part is equal to snlo or nnlo, the code uses $p_T^{\mathit{veto}}$ slicing, rather than 0-jettiness, in the calculation of higher-order contributions. In a resummed calculation, e.g. part is equal to resNLO or resNNLO, it enables the use of $p_T^{\mathit{veto}}$ resummation rather that $q_T$ resummation. In this case the value of the jet veto (ptveto) is set separately in the resummation block. Default is .false.

useBNR

Implements $p_T^{\mathit{veto}}$ formalism using the refactorized approach of Ref. [58]. Otherwise uses original ‘$B\times B\times S$’ factorization of below-cut cross-section into beam and soft functions (that gives identical results). Default is .true.

pdlabel

This specifies the parton distributions used in the case when the code has been built with PDFROUTINES = NATIVE. The choice of parton distribution is made by inserting the appropriate 7-character code from Table ?? or in Tables ?? and ?? for historical PDF sets. As mentioned above, this also sets the value of ${\alpha }_S(M_Z)$.

lhapdfset

Specifies the parton distributions used in the case when the code has been built with PDFROUTINES = LHAPDF. For a default global installation the PDFs reside in /usr/share/LHAPDF/ or /usr/local/share/LHAPDF, and the name equals the set name from https://lhapdf.hepforge.org/pdfsets.html, which is also the directory name of the sets. Multiple PDF sets separated by a space can be specified.

lhapdfmember

Specifies the individual members of the parton distribution sets. A value of zero corresponds to the central value for Hessian sets. In the case when multiple sets have been specified above, each one needs a member number separated by space.

dopdferrors

When this is set to .true., PDF uncertainties are calculated for every specified PDF set according to the routines provided by LHAPDF. The lhapdfmember numbers are ignored but must still be set for each member.

renscale

This parameter may be used to adjust the value of the renormalization scale. This is the scale at which ${\alpha }_S$ is evaluated and will typically be set to a mass scale appropriate to the process ($M_W$, $M_Z$, $m_t$ for instance).

facscale

This parameter may be used to adjust the value of the factorization scale and will typically be set to a mass scale appropriate to the process ($M_W$, $M_Z$, $m_t$ for instance).

dynamicscale

This character string is used to specify whether the renormalization, factorization and fragmentation scales are dynamic, i.e. recalculated on an event-by-event basis. If this string is set to ‘none’ then the scales are fixed for all events at the values specified by renscale, facscale as well as fragmentation_scale as defined further below.

The type of dynamic scale to be used is selected by using a particular string for the variable dynamicscale, as indicated in Table 6.10. Not all scales are defined for each process, with program execution halted if an invalid selection is made in the input file. The selection chooses a reference scale, ${\mu }_0$. The actual scales used in the code are then,

Note that, for simplicity, the fragmentation scale (relevant only for processes involving photons) is set equal to the renormalization scale. In some cases it is possible for the dynamic scale to become very large. This can cause problems with the interpolation of data tables for the PDFs and fragmentation functions. As a result if a dynamic scale exceeds a maximum of $60$ TeV (PDF) or $990$ GeV (fragmentation) this value is set by default to the maximum.

doscalevar

This additional option can be set to .true. to enable scale variation. It performs a variation of the scales used in 6.6 by a factor of two so that it surveys the additional possibilities,

The histograms corresponding to these different choices are included in the output file, from which an envelope of theoretical uncertainty may be constructed by the user.

maxscalevar

Number of additional scale variation points to choose, can be set to two or six. For two it just samples the first two variations as in Eq. 6.7.

hmass

Higgs pole mass

mt

Top-quark pole mass

mb

Bottom-quark pole mass

mc

Charm-quark pole mass

wmass

W-boson pole mass

zmass

Z-boson pole mass

inclusive

This logical parameter chooses whether the calculated cross-section should be inclusive in the number of jets found at NLO. An exclusive cross-section contains the same number of jets at next-to-leading order as at leading order. An inclusive cross-section may instead contain an extra jet at NLO.

algorithm

This specifies the jet-finding algorithm that is used, and can take the values ktal (for the Run II $k_T$-algorithm), ankt (for the “anti-$k_T$” algorithm [59]), cone (for a midpoint cone algorithm), hqrk (for a simplified cone algorithm designed for heavy quark processes) and none (to specify no jet clustering at all). The latter option is only a sensible choice when the leading order cross-section is well-defined without any jet definition: e.g. the single top process, $q{\overline{q}}^{\prime }\to t\overline{b}$, which is finite as $p_T(\overline{b})\to 0$.

ptjetmin, etajetmax

These specify the values of $p_{T,\min }$ and $|\eta {\text{|}}_{\max }$ for the jets that are found by the algorithm.

etajetmin

Optional parameter for setting a minimum jet rapidity $|\eta {\text{|}}_{\min }$.

ptjetmax

Optional parameter for setting maximum jet $p_{T,\max }$

Rcutjet

If the final state of the chosen process contains either quarks or gluons then for each event an attempt will be made to form them into jets. For this it is necessary to define the jet separation

so that after jet combination, all jet pairs are separated by $\mathrm{\Delta }R>$ Rcutjet.

userap

Optional parameter for using jet rapidity rather than pseudorapidity when performing jet cuts. Default is .true..

m34min, m34max, m56min, m56max, m3456min, m3456max

These parameters represent a basic set of mass cuts that are be applied to the calculated cross-section. The only events that contribute to the cross-section will have, for example, m34min $<$ m34$<$ m34max where m34 is the invariant mass of particles 3 and 4 that are specified by nproc. m34min$>0$ is obligatory for processes which can involve a virtual photon, such as nproc=31. By default, the maximum settings are set to $\sqrt{s}$.

makecuts

If this parameter is set to .false., then no additional cuts are applied to the events (apart from those in Sections 6.1.8 and 6.1.9) and the remaining parameters in this section are ignored. Otherwise, events will be rejected according to a set of cuts that is specified below. Further options may be implemented by editing src/User/gencuts_user.f90.

ptleptmin, etaleptmax

These specify the values of $p_{T,\min }$ and $|\eta {\text{|}}_{\max }$ for one of the leptons produced in the process. One can also introduce optional settings ptleptmax and etaleptmin.

etaleptveto

This should be specified as a pair of double precision numbers that indicate a rapidity range that should be excluded for the lepton that passes the above cuts.

ptminmiss

Specifies the minimum missing transverse momentum (coming from neutrinos).

ptlept2min, etalept2max

These specify the values of $p_{T,\min }$ and $|\eta {\text{|}}_{\max }$ for the remaining leptons in the process. This allows for staggered cuts where, for instance, only one lepton is required to be hard and central. One can also introduce optional settings ptlept2max and etalept2min.

etalept2veto

This should be specified as a pair of double precision numbers (separated by a space) that indicate a rapidity range that should be excluded for the remaining leptons.

m34transmin

For general processes, this specifies the minimum transverse mass of particles 3 and 4,

For the $W(\to \mathit{\ell \nu })\gamma$ process the role of this cut changes, to become instead a cut on the transverse cluster mass of the $(\mathit{\ell \gamma },\nu )$ system,

For the $\mathit{Z\gamma }$ process this parameter specifies a simple invariant mass cut,

A final mode of operation applies to the $\mathit{W\gamma }$ process and is triggered by a negative value of m34transmin. This allows simple access to the cut that was employed in v6.0 of the code:

In each case the screen output indicates the cut that is applied.

Rjlmin

Using the definition of $\mathrm{\Delta }R$ given above in Eq.6.8), requires that all jet-lepton pairs are separated by $\mathrm{\Delta }R>$ R(jet,lept)_min.

Rllmin

When non-zero, all lepton-lepton pairs must be separated by $\mathrm{\Delta }R>$ R(lept,lept)_min.

delyjjmin

This enforces a rapidity gap between the two hardest jets $j_1$ and $j_2$, so that: $|{\eta }^{j_1}-{\eta }^{j_2}|>$ delyjjmin.

jetsopphem

If this parameter is set to .true., then the two hardest jets are required to lie in opposite hemispheres, ${\eta }^{j_1}\cdot {\eta }^{j_2}<0$.

lbjscheme

This integer parameter provides no additional cuts when it takes the value 0. When equal to 1 or 2, leptons are required to lie between the two hardest jets. With the ordering ${\eta }^{j_{\text{−}}}<{\eta }^{j_{\text{+}}}$ for the rapidities of jets $j_1$ and $j_2$: lbjscheme = 1 : ${\eta }^{j_{\text{−}}}<{\eta }^{\mathrm{leptons}}<{\eta }^{j_{\text{+}}}$; lbjscheme = 2 : ${\eta }^{j_{\text{−}}}+$ Rcutjet$<{\eta }^{\mathrm{leptons}}<{\eta }^{j_{\text{+}}}-$Rcutjet.

ptbjetmin, etabjetmax

If a process involving $b$-quarks is being calculated, then these can be used to specify stricter values of $p_T^{\min }$ and $|\eta {\text{|}}^{\max }$ for $b$-jets. Similarly, values for ptbjetmax and etabjetmin can be specified.

fragmentation

This parameter is a logical variable that determines whether the production of photons by a parton fragmentation process is included. If fragmentation is set to .true., the code uses a standard cone isolation procedure (that includes LO fragmentation contributions in the NLO calculation). If fragmentation is set to .false., the code implements a Frixione-style photon cut [55],

In this equation, $R_0$, ${𝜖}_h$ and $n$ are defined by cone_ang, epsilon_h and n_pow respectively (see below). $E_{T,i}^j$ is the transverse energy of a parton, $E_T^{\gamma }$ is the transverse energy of the photon and $R$ is the separation between the photon and the parton using the usual definition

$n$ is an integer parameter which by default is set to 1.

fragmentation_set

A length eight character variable that is used to choose the particular photon fragmentation set. Currently implemented fragmentation functions can be called with ‘BFGSet_I’, ‘BFGSetII’ [60] or ‘GdRG__LO’ [61].

fragmentation_scale

A double precision variable that will be used to choose the scale at which the photon fragmentation is evaluated.

gammptmin

This specifies the value of $p_T^{\min }$ for the photon with the largest transverse momentum. Note that this cut, together with all the photon cuts specified in this section of the input file, are applied even if makecuts is set to .false.. One can also add an entry for gammptmax to cut on a range.

gammrapmax

This specifies the value of $|y{\text{|}}^{\max }$ for any photons produced in the process. One can also add an entry for gammrapmin to cut on a range.

gammpt2, gammpt3

The values of $p_T^{\min }$ for the second and third photons, ordered by $p_T$.

Rgalmin

Using the usual definition of $R$ above, this requires that all photon-lepton pairs are separated by $R>$ Rgalmin. This parameter must be non-zero for processes in which photon radiation from leptons is included.

Rgagamin

Using the usual definition of $R$ above, this requires that all photon pairs are separated by $R>$ Rgagamin.

Rgajetmin

Using the usual definition of $R$ above, this requires that all photon-jet pairs are separated by $R>$ Rgajetmin.

cone_ang

Fixes the cone size ($R_0$) for photon isolation. This cone is used in both forms of isolation.

epsilon_h

This cut controls the amount of radiation allowed in cone when fragmentation is set to .true.. If epsilon_h $<1$ then the photon is isolated using ${\sum <!--\; FUNCTION\; APPLICATION\; -->}_{\in R_0}{E}_T(\mathrm{had})<{𝜖}_h{p}_T^{\gamma }.$ Otherwise epsilon_h$>1$ sets $E_T(\mathit{max})$ in ${\sum <!--\; FUNCTION\; APPLICATION\; -->}_{\in R_0}{E}_T(\mathrm{had})<E_T(\mathit{max})$.

n_pow

When using the Frixione isolation prescription, the exponent $n$ in Eq. (6.13).

fixed_coneenergy

This is only operational when using the Frixione isolation prescription. If fixed_coneenergy is .false. then ${𝜖}_h$ controls the amount of hadronic energy allowed inside the cone using the Frixione isolation prescription (see above, Eq. (6.13)) If fixed_coneenergy is .true. then this formula is replaced by one where ${𝜖}_h{E}_T^{\gamma }\to {𝜖}_h$.

hybrid, R_inner

If hybrid is set to .true. use a hybrid isolation scheme with Frixione isolation on an inner cone of radius R_inner.

writetop

Write output histograms suitable as input for top-drawer.

writetxt

Write output histograms as whitespace-separated columns.

newstyle

Use the new plotting infrastructure introduced in MCFM-10.0

usesobol

When .true. and the number of MPI processes is a power of two, the Sobol sequence is used, see ref. [62], otherwise the MT19937 pseudo random number generator.

seed

Initialization seed for MT19937 pseudo random number generator.

precisiongoal

Relative precision goal for the integration.

readin

When .true. the automatically written snapshot from a previous run will be read-in to resume the integration.

writeintermediate

When .true. histograms are written after each Vegas iteration.

warmupprecisiongoal

Sets the relative precision goal for the warmup run. Unless this precision is reached, the number of calls for the warmup is increased.

warmupchisqgoal

Sets the ${\chi }^2$ per iteration goal for the warmup run. Unless the ${\chi }^2∕\text{it.}$ of the warmup is below this target, the number of calls for the warmup is increased.

c_phiq

Sets real Wilson coefficient of $\mathcal{𝒬}(3,33)\mathit{\phi q}$ for processes 164 and 169. See 13.40 and ref. [33].

c_phiphi

Sets real and imaginary part of the $\mathcal{𝒬}33\mathit{\phi ud}$ Wilson coefficient.

c_tw

Sets real and imaginary part of the $\mathcal{𝒬}33\mathit{uW}$ Wilson coefficient.

c_bw

Sets real and imaginary part of the $\mathcal{𝒬}33\mathit{dW}$ Wilson coefficient.

c_tg

Sets real and imaginary part of the $\mathcal{𝒬}33\mathit{uG}$ Wilson coefficient.

c_bg

Sets real and imaginary part of the $\mathcal{𝒬}33\mathit{dG}$ Wilson coefficient.

lambda

Scale $\Lambda$, see 13.40 and ref. [33].

enable_lambda4

Enable contributions of order $1∕{\Lambda }^4$ when set to .true..

disable_sm

When set to .true. the pure SM contributions are disabled, and just the SM-EFT interference and EFT contributions are calculated.

mode_anomcoup

When set to .true. at LO one can reproduce results obtained without power counting as in the anomalous couplings approach, see 13.40 and ref. [33].

nnlo_enable_light, nnlo_enable_heavy_prod, nnlo_enable_heavy_decay, nnlo_enable_interf_lxh, nnlo_enable_interf_lxd, nnlo_enable_interf_hxd, nnlo_fully_inclusive

At NNLO there are several different contributions from vertex corrections on the light-quark line, heavy-quark line in production, and heavy-quark line in the top-quark decay. Additionally there are one-loop times one-loop interference contributions between all three contributions. For a fully inclusive calculation without decay nnlo_fully_inclusive has to be set to ‘.true.‘ and the decay and decay interference parts have to be removed. Additionally jet requirements must be lifted. For further information see Section 13.39.

enable

Boolean flag to enable anomalous W-boson and Z-boson coupling contributions for certain processes. False has the same effect as setting all anomalous couplings to zero, but additionally skips computation of anomalous coupling code parts.

delg1_z

$\mathrm{\Delta }{g}_1^Z$ See section 13.24.

delk_z

$\mathrm{\Delta }{\kappa }^Z$ See section 13.24.

delk_g

$\mathrm{\Delta }{\kappa }^{\gamma }$ See sections 13.24 and 13.72.

lambda_z

${\Lambda }^Z$ See section 13.24.

lambda_g

${\Lambda }^{\gamma }$ See sections 13.24 and 13.72.

h1Z

$h_1^Z$ Anomalous couplings for $\mathit{Z\gamma }$ process at NNLO. See section 13.73.

h1gam

$h_1^{\gamma }$ See section 13.73.

h2Z

$h_2^Z$ See section 13.73.

h2gam

$h_2^{\gamma }$ See section 13.73.

h3Z

$h_3^Z$ See section 13.73.

h3gam

$h_3^{\gamma }$ See section 13.73.

h4Z

$h_4^Z$ See section 13.73.

h4gam

$h_4^{\gamma }$ See section 13.73.

tevscale

Form-factor scale, in TeV See section 13.24. No form-factors are applied to the anomalous couplings if this value is negative.

Qflag

This only has an effect when running a $W+2$ jets or $Z+2$ jets process. When .true., it includes the effect of four-quark processes. Please see section 13.10 below.

Gflag

This only has an effect when running a $W+2$ jets or $Z+2$ jets process. When .true., it includes the effect of two-quark, two-gluon processes. Please see section 13.10 below.

mtex

Sets the order $k=0,2,4$ of the $1∕m_t^k$ expansion for virtual corrections in the $H+$jet process 200. See section 13.43.

hwidth_ratio

For processes 123–126, 128–133 only, this variable provides a rescaling of the width of the Higgs boson. Couplings are rescaled such that the corresponding cross section close to the Higgs boson peak is unchanged. Further details of this procedure are given in arXiv:1311.3589.

cttH,cWWH

See arXiv:1311.3589.

debug

A logical variable which can be used during a debugging phase to mandate special behaviours. Passed by common block common/debug/debug.

verbose

A logical variable which can be used during a debugging phase to write special information. Passed in common block common/verbose/verbose.

new_pspace

A logical variable which can be used during a debugging phase to test alternative versions of the phase space. Passed in common block common/new_pspace/new_pspace.

spira

A logical variable. If spira is .true., we calculate the width of the Higgs boson by interpolating from a table calculated using the NLO code of M. Spira. The default value is .true.. Otherwise the LO value valid for low Higgs masses only is used.

noglue

A logical variable. The default value is .false.. If set to .true., no processes involving initial gluons are included.

ggonly

A logical variable. The default value is .false.. If set to .true., only the processes involving initial gluons in both hadrons are included.

gqonly

A logical variable. The default value is .false.. If set to .true., only the processes involving an initial gluon in one hadron and an initial quark or antiquark in the other hadron (or vice versa) are included.

omitgg

A logical variable. The default value is .false.. If set to .true., the gluon-gluon initial state is not included.

clustering

This logical parameter determines whether clustering is performed to yield jets. Only during a debugging phase should this variable be set to .false..

colourchoice

If colourchoice=0, all colour structures are included ($W,Z+2$ jets). If colourchoice=1, only the leading colour structure is included ($W,Z+2$ jets).

rtsmin

A minimum value of $\sqrt{s_{12}}$, which ensures that the invariant mass of the incoming partons can never be less than rtsmin.

reweight

Flag to set the use of the user-implemented reweighting procedure reweight_user in the routine src/User/gencuts_user.f90.

aii

A double precision variable which can be used to limit the kinematic range for the subtraction of initial-initial dipoles as suggested by Trocsanyi and Nagy [63]. The value aii=1 corresponds to standard Catani-Seymour subtraction.

aif

A double precision variable which can be used to limit the kinematic range for the subtraction of initial-final dipoles as suggested by Trocsanyi and Nagy [63]. The value afi=1 corresponds to standard Catani-Seymour subtraction.

afi

A double precision variable which can be used to limit the kinematic range for the subtraction of final-initial dipoles as suggested by Trocsanyi and Nagy [63]. The value afi=1 corresponds to standard Catani-Seymour subtraction.

aff

A double precision variable which can be used to limit the kinematic range for the subtraction of final-final dipoles as suggested by Trocsanyi and Nagy [63]. The value aff=1 corresponds to standard Catani-Seymour subtraction.

bfi

A double precision variable which can be used to limit the kinematic range for the subtraction of final-initial dipoles in the photon fragmentation case.

bff

A double precision variable which can be used to limit the kinematic range for the subtraction of final-final dipoles in the photon fragmentation case.