# Les Houches

## 2023 Session

• Use of wiki pages and slack. Wifi access/set-up.
• Important info about bus, lodging, facilities.
• Bulletins.

## Wikis of Previous sessions

#### Les Houches Themes

(Lyrics and Music)

## Help

2023:groups:smhiggs:ggf-background-vbf:start

## Gluon Fusion Background to VBF

##### Topic Ideas
• Study top mass dependence at NLO_FTapprox
• Compare to impact of HEJ (see slide 6)
• in HH, the effects were more sizeable [https://arxiv.org/pdf/1803.02463.pdf]; can we understand what differs for H+2j?
• A possible simple prescription for Powheg: use LO ratio (exact/HTL) evaluated on Born-projected kinematics as a first approximation.
##### Setup

Input parameters and settings

• $\sqrt{s} = 13.6\,\mathrm{TeV}$
• PDF set: PDF4LHC21_40
• $M_\mathrm{H} = 125.09\,\mathrm{GeV}$
• $m_\mathrm{t} = 172.5\,\mathrm{GeV}$
• $M_\mathrm{Z} = 91.1876\,\mathrm{GeV}$, $\Gamma_\mathrm{Z} = 2.4952\,\mathrm{GeV}$
• $M_\mathrm{W} = 80.379\,\mathrm{GeV}$, $\Gamma_\mathrm{W} = 2.085\,\mathrm{GeV}$
• G-mu scheme with $\alpha_{G_\mu} = 0.75652103079904\ldots \times 10^{-2}$ (from $G_\mu = 1.16638 \times 10^{-5}\,\mathrm{GeV}^{-2}$)
• central scale choice: $\mu_0^2 = (M_\mathrm{H}/2) \, \sqrt{ (M_\mathrm{H}/2)^2 + p_\mathrm{T,H}^2 }$ (Eq.(2) of 1506.02660)
##### Cuts/Binning

Event definition/selection:

• jets: anti-kT with $R=0.4$
• $p_{\mathrm{T},j} > 30\,\mathrm{GeV}$
• $|\eta_j| < 4.7$
• $m_{jj} > 300\,\mathrm{GeV}$
• $|\Delta y_{jj}| > 2$
• no rapidity selection on Higgs

Histograms and binning:

• double-differential ($m_{jj} \times p_\mathrm{T,H}$): [300, 500, 700, 900, 1100, ∞] × [0, 80, 120 ,260, 500, 850, ∞]
• double-differential ($m_{jj} \times \Delta\phi_{jj}$): [300, 500, 700, 900, 1100, ∞] × [0, π/4, π/2, 3π/4, π]
• double-differential ($m_{jj} \times \Delta y_{jj}$): [300, 500, 700, 900, 1100, ∞] × [2, 4, 5, 6, 7, ∞]
• double-differential ($p_\mathrm{T,H} \times \Delta y_{jj}$): [0, 80, 120 ,260, 500, 850, ∞] × [2, 4, 5, 6, 7, ∞]

Underlying event tunes in CMS:

• 'Tune:preferLHAPDF = 2',
• 'Main:timesAllowErrors = 10000',
• 'Check:epTolErr = 0.01',
• 'Beams:setProductionScalesFromLHEF = off',
• 'SLHA:minMassSM = 1000.',
• 'ParticleDecays:limitTau0 = on',
• 'ParticleDecays:tau0Max = 10',
• 'Tune:pp 14',
• 'MultipartonInteractions:ecmPow=0.03344',
• 'MultipartonInteractions:bProfile=2',
• 'MultipartonInteractions:pT0Ref=1.41',
• 'MultipartonInteractions:coreFraction=0.63',
• 'ColourReconnection:range=5.176',
• 'SigmaTotal:zeroAXB=off',
• 'SpaceShower:alphaSorder=2',
• 'SpaceShower:alphaSvalue=0.118',
• 'SigmaProcess:alphaSvalue=0.118',
• 'SigmaProcess:alphaSorder=2',
• 'MultipartonInteractions:alphaSvalue=0.118',
• 'MultipartonInteractions:alphaSorder=2',
• 'TimeShower:alphaSorder=2',
• 'TimeShower:alphaSvalue=0.118',
• 'SigmaTotal:mode = 0',
• 'SigmaTotal:sigmaEl = 22.08',
• 'SigmaTotal:sigmaTot = 101.037',
• 'PDF:pSet=LHAPDF6:NNPDF31_nnlo_as_0118',