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

Gluon Fusion Background to VBF

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.

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)

Event definition/selection:

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: