herwig 7 - conference.ippp.dur.ac.uk · herwig 7 current status herwig 7.1 focus on standard model...
TRANSCRIPT
Herwig 7
Herwig 7
Peter Richardson
CERN Theory Division & IPPP Durham
Durham: 20th April
Peter Richardson Herwig 7
Herwig 7
Introduction
Outline
Introduction
Current Status
BSM in Herwig
Conclusions & Future Plans
Peter Richardson Herwig 7
Herwig 7
Introduction
Introduction
HERWIG was originally designed as a program forunderstanding hadronic physics.
Strong emphasis on the accurate simulation of QCD.
From HERWIG 6 strong emphasis on the study of BSM:
SUSY (including RPV and εijk colour flows);Spin Correlations;RS, . . . .
Starting in 2000 major rewrite in C++ (Herwig++)
The old code was becoming impossible to maintain and a lotof physics we wanted to implement, e.g. QCD radiation fromsquarks and gluinos, was impossible to implement.
Peter Richardson Herwig 7
Herwig 7
Introduction
Introduction
While still emphasising the simulation of QCD including BSMwas an important design feature:
Better handling of weird colour structures;Coding of Feynman rules rather than matrix elements;automatic calculation of 1 → 2, 1 → 3 decays (some 1 → 4)and 2 → 2 scattering processes;Use helicity amplitudes (based on HELAS formalism);Consistently include spin correlations.
Made adding new models much easier.
Sophisticated simulation of BSM processes.
Peter Richardson Herwig 7
Herwig 7
Introduction
Tau Decays
h0,A0 → τ+τ− → π+ντπ−ντ τL → τ−χ0
1 → π−π0ντ χ01
Correlations possible due to consistent implementation ofBSM physics and τ decays.
Peter Richardson Herwig 7
Herwig 7
Current Status
Herwig 7
For the last 10 years we have been working towards a goal ofa release that met a (moving) definition intended fully replacethe FORTRAN HERWIG program.
Over time that has evolved as the needs of the experimentaland phenomenological communities have developed over thelast ten years.
Precision is now the key and matching to higher ordersabsolutely essential.
Peter Richardson Herwig 7
Herwig 7
Current Status
Herwig 7.1
Focus on Standard Model physics.
Default is to have NLO matrix elements matched to theparton shower.
Fully automated, so that users can choose their process andeverything is set up for them.
Both multiplicative (POWHEG) and additive (MC@NLO) typematching
Option of two different parton showers, angular-ordered anddipole.
NLO merging with the dipole shower
Much better documentation
Finally completely replaces FORTRAN HERWIG.
Peter Richardson Herwig 7
Herwig 7
Current Status
NLO Matching
b
b
bb b b b b
bb
bb
bb
bb
bb
b
b
b
Herwig 7MadGraph / ColorFull / OpenLoops
ALEPH Datab
Herwig++ 2.7 LO ⊗ PSLO ⊗ PSNLO ⊕ PSNLO ⊗ PSNLO ⊕ Dipoles
10−2
10−1
1
10 1
1-Thrust, 1 − T (charged)
1/N
dN
/d(1
−T)
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
0.6
0.8
1
1.2
1.4
1 − T
MC
/Dat
a
b
b
b
b b
b
b
Herwig 7MadGraph / ColorFull / OpenLoops
ALEPH Datab
Herwig++ 2.7 LO ⊗ PSLO ⊗ PSQCD ⊗ QED ⊗ PSNLO ⊕ PS
10−3
10−2
10−1
1
10 1
10 2
10 3Photon Fragmentation in 3-jet events with ycut = 0.1
1/σ
dσ(3
−je
t)/
dz×
103
0.7 0.75 0.8 0.85 0.9 0.95 1.0-3 σ-2 σ-1 σ0 σ1 σ2 σ3 σ
zγ
(MC
−d
ata)
Herwig 7.0 at LEP – new tune available with the release.Several improvements to angular ordered shower.
Tons of plots using all combinations at: https://herwig.hepforge.org/plots/herwig7.0/
Peter Richardson Herwig 7
Herwig 7
Current Status
NLO Matching
b b b b b b b b b b b b b b b b b bb b b b b
bb
bb
bb
b
Herwig 7MadGraph / ColorFull / OpenLoops
CMS Datab
LO ⊕ PSNLO ⊕ PSNLO ⊗ PSNLO ⊕ Dipoles
10−4
10−3
10−2
10−1
1
∆φ(Z, J1),√
s = 7 TeV
1 σdσ dφ
0 0.5 1 1.5 2 2.5 3
0.6
0.8
1
1.2
1.4
∆φ(Z, J1) [rad]
MC
/Dat
a
b
b
b
b
b
b
b
bb
bb
b b b b b b b
Herwig 7MadGraph / ColorFull / OpenLoops
ATLAS Datab
Herwig++ 2.7 LO ⊗ PSLO ⊕ PSNLO ⊕ PSNLO ⊗ PS
0.65
0.7
0.75
0.8
0.85
0.9
0.95
1.0
Gap fraction vs. Qsum for veto region: |y| < 2.1
f gap
50 100 150 200 250 300 350 400
0.96
0.98
1.0
1.02
1.04
Qsum [GeV]
MC
/Dat
a
Z+jet events from CMS and top pairs from ATLAS.Matchbox using MadGraph, ColorFull and OpenLoops.
Tons of plots using all combinations at: https://herwig.hepforge.org/plots/herwig7.0/
Peter Richardson Herwig 7
Herwig 7
Current Status
NLO Matching
b
b
b
b
b
b
bb
bb
b b b b b b b b bb
bbbb b
b
Datab
Hw 7.0 LO ⊕ PS
Hw 7.0 NLO⊕ PS
Hw 7.0 NLO⊗ PS
Hw 7.0 NLO⊕ Dipoles
10−1
1
10 1
Transverse EEC
(1/
σ)d
Σ/d(cos
φ)
-1 -0.5 0 0.5 1
0.6
0.8
1
1.2
1.4
cos φ
MC/Data
b
b
b
b
bb
b
b
b
b
b
b
b
b
b
bb
b
Datab
Hw++ 2.7 LO ⊕ PS
Hw 7.0 LO ⊕ PS
Hw 7.0 NLO⊕ PS
Hw 7.0 NLO⊗ PS
Hw 7.0 NLO⊕ Dipoles
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014Cambridge-Aachen jets, R=1.2, 200 GeV < p⊥ < 300 GeV
1/
σd
σ/dm
[GeV
−1]
20 40 60 80 100 120 140 160 180
0.6
0.8
1
1.2
1.4
Jet mass [GeV]
MC/Data
Jets from CMS and ATLAS.Matchbox using MadGraph, ColorFull and OpenLoops.
Tons of plots using all combinations at: https://herwig.hepforge.org/plots/herwig7.0/
Peter Richardson Herwig 7
Herwig 7
Current Status
NLO Matching
bbbbbbbbbbbbbbb
bb
bb
bb
bb
bb
bb
bb
bb
b
b
Datab
Hw 7.0 LO ⊕ PS
Hw 7.0 NLO⊕ PS
Hw 7.0 NLO⊗ PS
Hw 7.0 NLO⊕ Dipoles
10−3
10−2
10−1
1
10 1
10 2
10 3
10 4
10 5
CMS, pp,√s = 7 TeV, anti-kT, R=0.5 (|y| < 0.5)
d2σ/dpTdy(pb/GeV
)
200 400 600 800 1000 1200
0.6
0.8
1
1.2
1.4
pT (GeV)
MC/Data
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
b
Datab
Hw++ 2.7 LO ⊕ PS
Hw 7.0 LO ⊕ PS
Hw 7.0 NLO⊕ PS
Hw 7.0 NLO⊗ PS
Hw 7.0 NLO⊕ Dipoles
10−510−410−310−210−1
110 110 210 310 410 510 610 7
Incl. jet double-diff. x-section, anti-kt 0.4 (0.3 ≤ |y| < 0.8)
d2σ/dp
⊥dy[pb/GeV
]
200 400 600 800 1000 1200 1400
0.6
0.8
1
1.2
1.4
p⊥ [GeV]
MC/Data
Jets from CMS and ATLAS.Matchbox using MadGraph, ColorFull and OpenLoops.
Tons of plots using all combinations at: https://herwig.hepforge.org/plots/herwig7.0/
Peter Richardson Herwig 7
Herwig 7
Current Status
NLO Matching
b
b
b
b
b
bb
b
b
b
Datab
Hw++ 2.7 LO ⊕ PS
Hw 7.0 LO ⊕ PS
Hw 7.0 NLO⊕ PS
Hw 7.0 NLO⊗ PS
Hw 7.0 NLO⊕ Dipoles
10−3
10−2
10−1
1
10 1Di-jet azimuthal decorrelation, p
leadingT > 300 GeV
1 σd
σd
∆φ[rad
−1]
1.6 1.8 2 2.2 2.4 2.6 2.8 3
0.6
0.8
1
1.2
1.4
∆φ [rad]
MC/Data
b
b
b
b
b
b
Datab
Hw++ 2.7 LO ⊕ PS
Hw 7.0 LO ⊕ PS
Hw 7.0 NLO⊕ PS
Hw 7.0 NLO⊗ PS
Hw 7.0 NLO⊕ Dipoles
10 1
10 2
10 3
10 4
10 5Measurement of forward+central jets at
√s = 7TeV
d2σ
dpTd
η[pb/GeV
]
40 60 80 100 120 140
0.6
0.8
1
1.2
1.4
Forward Jet pT [GeV]
MC/Data
Jets from CMS and ATLAS.Matchbox using MadGraph, ColorFull and OpenLoops.
Tons of plots using all combinations at: https://herwig.hepforge.org/plots/herwig7.0/
Peter Richardson Herwig 7
Herwig 7
Current Status
NLO Merging
bb
b
bb
bb
bb b b b b
bb
bb
bb
bb
bb
b
b
b
b
b
bHerwig 7.1MadGraph/OpenLoops/ColorFull
OPAL Datab
ee(0)ee(0,1,2)ee(0*,1*,2)ee(0*,1*,2*,3)
10−2
10−1
1
10 1
10 2
10 3Differential 3-jet rate with Durham algorithm (91.2 GeV)
1/σ
dσ
/d
y 34
10−4 10−3 10−2 10−1
0.60.70.80.91.01.11.21.31.4
yDurham34
MC
/Dat
a
b
b
b
b
b
b
b
b
Herwig 7.1MadGraph/OpenLoops/ColorFull
ATLAS Datab
Z(0)Z(0,1,2)Z(0,1,2), ρ ∈ [5,20] GeVZ(0*,1*,2)Z(0*,1*,2,3) ρ = 15 GeV
10−3
10−2
10−1
1
10 1
10 2
Inclusive jet multiplicity
σ(Z
/γ
∗ (→
ℓ+ℓ−
)+≥
Nje
t)[p
b]
0 1 2 3 4 5 6 7
0.20.40.60.8
11.21.41.61.8
Njet
MC
/Dat
a
J. Bellm, S. Gieseke, S. Platzer Eur.Phys.J. C78 (2018) no.3, 244
Peter Richardson Herwig 7
Herwig 7
Current Status
Uncertainities
Eur.Phys.J. C76 (2016) no.12, 665 Bellm et.al.
Peter Richardson Herwig 7
Herwig 7
Current Status
Reweighting
AO (µR/√
2, µF /√
2)
AO (√
2µR,√
2µF )
AO (µR, µF )10−7
10−6
10−5
10−4
10−3
10−2
1/σ
×dσ/d
p⊥
(H)
[1/G
eV]
1 10 1 10 2
0.6
0.8
1
1.2
1.4
p⊥(H) [GeV]
Rew
eigh
t/D
irec
t
Dipole Shower√
2µR
Dipole Shower µR
Dipole Shower µR/√
2
10−5
10−4
10−3
10−2
10−1
1
10 1
1 σdσ
d(1
−T)
0 0.1 0.2 0.3 0.4 0.5
0.6
0.8
1
1.2
1.4
1 − T
Rew
eigh
t/D
irec
t
Bellm et.
al. Phys.Rev. D94 (2016) no.3, 034028
Peter Richardson Herwig 7
Herwig 7
Current Status
Quark-Gluon discrimination
Lot of study as part of the2015 Les Houches workshopGras et. al., JHEP 1707 (2017) 091.
Finally some real data wecan compare do, not justneutral net/BDT outputs,ATLAS, Eur. Phys. J. C76(6), 322 (2016).
Improvements to thenon-perturbative modelingand tuning in Herwig 7.1Reichelt, PR and Siodmok, arXiv:1708.01491
b bb
b
b
b
b
bb
b
b
b
b
b
b
b
b
Hw 7.1 p⊥-q2-BHw 7.1 p⊥-p⊥-BHw++ 2.7Hw 7.0Datab
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
Charged particle multiplicity, E∗g = 14.24 GeV
P(n
ch.
gluo
n)
0 2 4 6 8 10 12 14 160.50.60.70.80.91.01.11.21.31.4
nch.gluon
MC
/Dat
ab b b
b
b
b
b
b b
b
b
b
b
b
bb
b
Hw 7.1 p⊥-q2-BHw 7.1 p⊥-p⊥-BHw++ 2.7Hw 7.0Datab
0
0.05
0.1
0.15
0.2
Charged particle multiplicity, E∗g = 17.72 GeV
P(n
ch.
gluo
n)
0 2 4 6 8 10 12 14 160.50.60.70.80.91.01.11.21.31.4
nch.gluon
MC
/Dat
a
Peter Richardson Herwig 7
Herwig 7
Current Status
Quark-Gluon discrimination
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
(0,0) (2,0) (1,0.5) (1,1) (1,2)
Q=200 GeV
R=0.6
LL
Sep
arat
ion
: Δ
Angularity: (κ,β)
p⊥-q2-B, hadron-level
baseline
no g→qq‾no CR
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
(0,0) (2,0) (1,0.5) (1,1) (1,2)
pTmin=100 GeV
R=0.4
Sep
arat
ion
: Δ
Angularity: (κ,β)
Hadron-level, plain jet
Pythia 8.215
Hw++ 2.7.1
Hw 7.1 p⊥-q2-B
Hw 7.1 p⊥-p⊥-B
Sherpa 2.2.1
Peter Richardson Herwig 7
Herwig 7
Current Status
Soft Physics
Inclusion of diffraction
New soft model.
P
pA
pB
pr1
pr2
q
q
g
g
. . .
b
b
b
b
bbb b
bb b b b b b b b b b b b b b b b b b b b b b b b b b b b
Datab
new, χ2/n = 0.59H7.0, χ2/n = 796.13
10−1
1
10 1
10 2
Rapidity gap size in η starting from η = ±4.7, pT > 200 MeV
dσ
/d
∆η
F[m
b]
0 1 2 3 4 5 6 7 8
0.6
0.8
1
1.2
1.4
∆ηF
MC
/Dat
a
S. Gieseke, F. Loshaj, P. Kirchgaeßer Eur.Phys.J. C77 (2017) no.3, 156
Peter Richardson Herwig 7
Herwig 7
Current Status
Baryonic Colour Reconnection
Allow recombination ofmesonic clusters to givebaryonic ones.
Based on proximity inmomentum space
Include non-perturbativeg → ss splitting in thecluster model.
b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b bbb b
bb
bHerwig 7
ALICE Datab
Herwig 7.1 defaultnew model
10−4
10−3
10−2
10−1
Charged Multiplicity√
(s) = 7 TeV
dN
/d
Nch
10 20 30 40 50 60 70
0.6
0.8
1
1.2
1.4
Nch
MC
/Dat
a
S. Gieseke, P. Kirchgaeßer, Simon Platzer Eur.Phys.J. C78 (2018) no.2, 99
Peter Richardson Herwig 7
Herwig 7
Current Status
Baryonic Colour Reconnection
b
b bbbbbbbbbbbbbbb b
bb
b
b
b
bHerwig 7
CMS Datab
Herwig 7.1 defaultbaryonic reconnectiong → ss splittingsnew model
10−4
10−3
10−2
10−1
1
K0S transverse momentum distribution at
√s = 7 TeV
(1/
NN
SD)
dN/
dpT
(GeV
/c)
−1
0 2 4 6 8 10
0.6
0.8
1
1.2
1.4
K0S pT [GeV/c]
MC
/Dat
a
b
bb b b b b b
bb b b
bb
bb
b bb
b
b
b
Herwig 7
CMS Datab
Herwig 7.1 defaultbaryonic reconnectiong → ss splittingsnew model
10−4
10−3
10−2
10−1
Ξ− transverse momentum distribution at√
s = 7 TeV
(1/
NN
SD)
dN/
dpT
(GeV
/c)
−1
0 1 2 3 4 5 6
0.6
0.8
1
1.2
1.4
Ξ− pT [GeV/c]
MC
/Dat
a
S. Gieseke, P. Kirchgaeßer, Simon Platzer Eur.Phys.J. C78 (2018) no.2, 99
Peter Richardson Herwig 7
Herwig 7
BSM in Herwig
BSM in Herwig
Most of the work over the last 10 years has focused onsimulation of Standard Model processes.
Still a number of BSM improvements:Handling of colour sextets;More BSM models;full correlations (i.e. including in shower);use τ decay currents for nearly degenerate BSM decays.
Major improvement with the ability to use models in the UFOformat
python ufo2herwig program converts UFO to C++ codeimplementing the model.can then be used like an internal model with simulation ofproduction, decay and QCD radiation from the BSM particles.
Most models can be used but limited to the perturbative spinand colour structures.
Peter Richardson Herwig 7
Herwig 7
BSM in Herwig
Contour
One important use case forHerwig
Uses:
UFO interface;ability to generateinclusive signals.
500 1000 1500 2000 2500 3000
MZ′ [GeV]
400
800
1200
1600
2000
Mdm
[GeV
]
J. Butterworth, D. Grellscheid, M. Kramer, B. Sarrazin, D. Yallup arXiv:1606.05296
Peter Richardson Herwig 7
Herwig 7
BSM in Herwig
Future
The type of BSM we need to simulate has changed.
Previously complete models with vertices having theperturbative form.Now simplified models and effective theories.
Next minor release, 7.1.4, will include some improvements
Some effective vertices, mainly for SSS, VSS, VVS, and VVVSfor models with different Higgs couplings
Next major release, 7.2, handling of general Lorentz structuresfor the vertices and more colour structures.
Peter Richardson Herwig 7
Herwig 7
BSM in Herwig
Example: SUSY model with goldstino and gravitino
Model with:
spin- 32 particles;
complicated Diracstructures;εαβγδ in many vertices;
Tough test for automaticparsing of the vertices.
Excellent agreement withMC5-aMCNLO.
Process σ/pb Ratio Fractional χ
Hw 7 Mad Differencegu → u1gld (27.20200 ± 0.0040) × 10−1 (27.21160 ± 0.0079) × 10−1 0.9996 -0.0002 -1.0852gu → u1grv (18.53800 ± 0.0030) × 10−1 (18.53830 ± 0.0044) × 10−1 1.0000 -0.0000 -0.0564gu → u4gld (28.13400 ± 0.0040) × 10−1 (28.13260 ± 0.0085) × 10−1 1.0000 0.0000 0.1495gu → u4grv (19.48900 ± 0.0030) × 10−1 (19.49400 ± 0.0048) × 10−1 0.9997 -0.0001 -0.8891
gs → d2gld (1.11250 ± 0.0002) × 10−1 (1.11264 ± 0.0003) × 10−1 0.9999 -0.0001 -0.4102
gs → d2grv (1.08280 ± 0.0002) × 10−1 (1.08255 ± 0.0003) × 10−1 1.0002 0.0001 0.7631
gs → d5gld (1.22070 ± 0.0002) × 10−1 (1.22098 ± 0.0003) × 10−1 0.9998 -0.0001 -0.7607
gs → d5grv (1.22890 ± 0.0002) × 10−1 (1.22904 ± 0.0003) × 10−1 0.9999 -0.0001 -0.4333gc → u2gld (7.69000 ± 0.0010) × 10−2 (7.68954 ± 0.0020) × 10−2 1.0001 0.0000 0.2080gc → u2grv (7.61300 ± 0.0010) × 10−2 (7.61320 ± 0.0017) × 10−2 1.0000 -0.0000 -0.1001gc → u5gld (8.06500 ± 0.0010) × 10−2 (8.06697 ± 0.0021) × 10−2 0.9998 -0.0001 -0.8579gc → u5grv (8.12600 ± 0.0010) × 10−2 (8.12763 ± 0.0018) × 10−2 0.9998 -0.0001 -0.7919
gb → d3gld (5.65120 ± 0.0008) × 10−2 (5.64113 ± 0.0014) × 10−2 1.0018 0.0009 6.2993
gb → d3grv (6.21400 ± 0.0010) × 10−2 (6.20548 ± 0.0013) × 10−2 1.0014 0.0007 5.1251
gb → d6gld (4.94500 ± 0.0008) × 10−2 (4.95255 ± 0.0012) × 10−2 0.9985 -0.0008 -5.1105
gb → d6grv (5.20610 ± 0.0008) × 10−2 (5.21305 ± 0.0012) × 10−2 0.9987 -0.0007 -4.8722
gd → d∗
1gld (2.12470 ± 0.0003) × 10−1 (2.12507 ± 0.0005) × 10−1 0.9998 -0.0001 -0.5958
gd → d∗
1grv (2.01050 ± 0.0003) × 10−1 (2.01034 ± 0.0005) × 10−1 1.0001 0.0000 0.2877
gd → d∗
4gld (2.32600 ± 0.0004) × 10−1 (2.32610 ± 0.0006) × 10−1 1.0000 -0.0000 -0.1367
gd → d∗
4grv (2.27300 ± 0.0004) × 10−1 (2.27331 ± 0.0005) × 10−1 0.9999 -0.0001 -0.4704gu → u∗
1gld (1.71460 ± 0.0003) × 10−1 (1.71493 ± 0.0004) × 10−1 0.9998 -0.0001 -0.6189gu → u∗
1grv (1.65060 ± 0.0003) × 10−1 (1.65038 ± 0.0004) × 10−1 1.0001 0.0001 0.4498gu → u∗
4gld (1.79670 ± 0.0003) × 10−1 (1.79669 ± 0.0004) × 10−1 1.0000 0.0000 0.0188gu → u∗
4grv (1.75910 ± 0.0003) × 10−1 (1.75882 ± 0.0004) × 10−1 1.0002 0.0001 0.5742
gs → d∗
2gld (9.70200 ± 0.0010) × 10−2 (9.70334 ± 0.0024) × 10−2 0.9999 -0.0001 -0.5159
gs → d∗
2grv (9.59600 ± 0.0010) × 10−2 (9.59757 ± 0.0022) × 10−2 0.9998 -0.0001 -0.6553
gs → d∗
5gld (1.06630 ± 0.0002) × 10−1 (1.06679 ± 0.0003) × 10−1 0.9995 -0.0002 -1.4664
gs → d∗
5grv (1.09190 ± 0.0002) × 10−1 (1.09190 ± 0.0002) × 10−1 1.0000 -0.0000 -0.0032gc → u∗
2gld (7.69000 ± 0.0010) × 10−2 (7.68954 ± 0.0020) × 10−2 1.0001 0.0000 0.2080gc → u∗
2grv (7.61300 ± 0.0010) × 10−2 (7.61320 ± 0.0017) × 10−2 1.0000 -0.0000 -0.1001gc → u∗
5gld (8.06500 ± 0.0010) × 10−2 (8.06697 ± 0.0021) × 10−2 0.9998 -0.0001 -0.8579gc → u∗
5grv (8.12600 ± 0.0010) × 10−2 (8.12763 ± 0.0018) × 10−2 0.9998 -0.0001 -0.7919
gb → d∗
3gld (5.65120 ± 0.0008) × 10−2 (5.64113 ± 0.0014) × 10−2 1.0018 0.0009 6.2993
gb → d∗
3grv (6.21400 ± 0.0010) × 10−2 (6.20548 ± 0.0013) × 10−2 1.0014 0.0007 5.1251
gb → d∗
6gld (4.94500 ± 0.0008) × 10−2 (4.95255 ± 0.0012) × 10−2 0.9985 -0.0008 -5.1105
15
Peter Richardson Herwig 7
Herwig 7
Conclusions
Long Term future
We are now as far from thestart of the redevelopmentof Herwig as that was fromthe start of the project.
1990 1995 2000 2005 2010 2015Date
0
100000
200000
300000
400000
500000
Line
s
Lines HwAuthors Hw
0
2
4
6
8
10
12
14
16
Auth
ors
Peter Richardson Herwig 7
Herwig 7
Conclusions
Long Term future
We are now as far from thestart of the redevelopmentof Herwig as that was fromthe start of the project.
The number of lines is againabout a factor of 10 morethan when the frameworkwas designed.
1990 1995 2000 2005 2010 2015Date
0
100000
200000
300000
400000
500000
Line
s
Lines Hw++Lines HwAuthors Hw++Authors Hw
0
2
4
6
8
10
12
14
16
Authors
Peter Richardson Herwig 7
Herwig 7
Conclusions
Long Term future
We are now as far from thestart of the redevelopmentof Herwig as that was fromthe start of the project.
The number of lines is againabout a factor of 10 morethan when the frameworkwas designed.
1990 1995 2000 2005 2010 2015Date
0
100000
200000
300000
400000
500000
Line
s
Lines Hw++Lines HwAuthors Hw++Authors Hw
0
2
4
6
8
10
12
14
16
Authors
Not as bad as for FORTRAN as the structure was better inthe first place but clearly for the next stage of developmentsome significant restructuring of parts of the code will berequired.
Peter Richardson Herwig 7
Herwig 7
Conclusions
Conclusions
The HERWIG project has taken over 30 years to reach thecurrent state-of-the-art.
It has been a constant series of incremental developmentscombined with occasional major changes in how we simulateevents such as the move to NLO.
Hopefully the next thirty years will see as much development.
However not obvious that much more is currently needed forBSM signals.
Peter Richardson Herwig 7