Higgs probes of top quark contact interactions and their interplay with the Higgs self-coupling

We present the calculation of the contribtuions from the chromomagnetic and four-top-quark-operators within Standard Model Effective Field Theory (SMEFT) to Higgs boson pair production in gluon fusion, combined with QCD corrections that are at NLO with full mt-dependence for the leading operators. We study the effects of these operators on the total cross section and the invariant mass distribution of the Higgs-boson pair, at $$\sqrt{s}$$ = 13.6 TeV. These subleading operators are implemented in the generator ggHH_SMEFT, in the same Powheg-Box-V2 framework as the leading operators, such that their effects can be easily studied in a unified setup.

Section: Amplitude Structure Involving Four-top Operatorsmentioning

confidence: 99%

Section: Amplitude Structure Involving Four-top Operatorsmentioning

confidence: 99%

Combining chromomagnetic and four-fermion operators with leading SMEFT operators for gg → hh at NLO QCD

Heinrich,

Lang

2024

“…Higgs self-coupling [9][10][11][12] to the Higgs pair production. However, the sensitivity to the Higgs self-coupling from single Higgs measurements diminishes once other new physics effects modifying also the single Higgs rates are included [13,14].…”

Section: Jhep11(2022)045mentioning

confidence: 99%

Machine learning the trilinear and light-quark Yukawa couplings from Higgs pair kinematic shapes

Alasfar

Gröber

Grojean

et al. 2022

Self Cite

Revealing the Higgs pair production process is the next big challenge in high energy physics. In this work, we explore the use of interpretable machine learning and cooperative game theory for extraction of the trilinear Higgs self-coupling in Higgs pair production. In particular, we show how a topological decomposition of the gluon-gluon fusion Higgs pair production process can be used to simplify the machine learning analysis flow. Furthermore, we extend the analysis to include $$ q\overline{q} $$ q q ¯ → hh production, which is strongly suppressed in the Standard Model, to extract the trilinear Higgs coupling and to bound large deviations of the light-quark Yukawa couplings from the Standard Model values. The constraints on the rescaling of the trilinear Higgs self-coupling, κλ, and the rescaling of light-quark Yukawa couplings, κu and κd, at HL-LHC (FCC-hh) from single parameter fits are:$$ {\displaystyle \begin{array}{c}{\kappa}_{\lambda }=\left[0.53,1.7\right]\ \left(\left[0.97,1.03\right]\right)\\ {}{\kappa}_u=\left[-470,430\right]\ \left(\left[-58,55\right]\right)\\ {}{\kappa}_d=\left[-360,360\right]\ \left(\left[-26,28\right]\right)\end{array}} $$ κ λ = 0.53 1.7 0.97 1.03 κ u = − 470 430 − 58 55 κ d = − 360 360 − 26 28 We show that the simultaneous modification of the Yukawa couplings can dilute the constraints on the trilinear coupling significantly. We perform similar analyses for FCC-hh. We discuss some motivated flavourful new physics scenarios where such an analysis prevails.

“…1 The SMEFiT collaboration subsequently made a global analysis that included SMEFT effects at quadratic order [7], assuming that the precision electroweak data are consistent with the SM. Other global fits have been performed for various combinations of electroweak, diboson and Higgs data, e.g., [8][9][10][11][12][13][14][15], as well as separate fits to mainly top measurements, e.g., [16][17][18][19][20][21][22][23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

SMEFT analysis of mW

Bagnaschi

Ellis

Madigan

et al. 2022

We use the Fitmaker tool to incorporate the recent CDF measurement of mW in a global fit to electroweak, Higgs, and diboson data in the Standard Model Effective Field Theory (SMEFT) including dimension-6 operators at linear order. We find that including any one of the SMEFT operators $$ \mathcal{O} $$ O HWB, $$ \mathcal{O} $$ O HD, $$ \mathcal{O} $$ O ℓℓ or $$ {\mathcal{O}}_{H\ell}^{(3)} $$ O H ℓ 3 with a non-zero coefficient could provide a better fit than the Standard Model, with the strongest pull for $$ \mathcal{O} $$ O HD and no tension with other electroweak precision data. We then analyse which tree-level single-field extensions of the Standard Model could generate such operator coefficients with the appropriate sign, and discuss the masses and couplings of these fields that best fit the CDF measurement and other data. In particular, the global fit favours either a singlet Z′ vector boson, a scalar electroweak triplet with zero hypercharge, or a vector electroweak triplet with unit hypercharge, followed by a singlet heavy neutral lepton, all with masses in the multi-TeV range for unit coupling.