One of the LHC's priorities, following the discovery of the Higgs boson, is to observe the production of Higgs pairs and to measure the Higgs tri-linear coupling $\lambda_{3H}$.
Due to the rarity of di-Higgs production, measuring $\lambda_{3H}$ has proven to be highly challenging. Exclusion limits have been observed using a variety of approaches, including cut-based methods and boosted...
The discovery of the Higgs boson ten years ago and successful measurement of the Higgs boson couplings to third generation fermions by ATLAS and CMS mark great milestones for HEP. The much weaker coupling to the second generation quarks predicted by the SM makes the measurement of the Higgs-charm coupling much more challenging. With the full run-2 data and with the advent of ML flavour tagging...
The measurement of the production of Higgs boson pairs (HH) at the LHC allows the exploration of the Higgs boson interaction with itself and is thus a fundamental test of the Standard Model theory and has a key role in the determination of the Higgs boson nature. The most recent results from the CMS collaboration on measurements of non-resonant HH production using different final states and...
Accurately computing the decay rate of metastable vacua in quantum field theory hinges on a precise evaluation of functional determinants arising from quantum fluctuations. In this presentation, we explore recent advances in the regularisation and evaluation of these determinants. The first part introduces a streamlined method to regularize functional determinants for fields of spin 0, 1/2,...
We present the program package ${\tt ggxy}$, which in its first version can be used to calculate partonic and hadronic cross sections to Higgs boson pair production at NLO QCD. The 2-loop virtual amplitudes are implemented using analytical approximations in different kinematic regions, while all other parts of the calculation are exact. This implementation allows to freely modify the masses of...
To fully characterize the Higgs boson, it is important to establish whether it presents coupling properties that are not expected in the Standard Model of particle physics. These can probe BSM effects, such as CP conserving or CP violating couplings to particles with masses not directly accessible at the LHC through virtual quantum loops. In this talk we will present the most recent searches...
In this talk, the latest results from the CMS experiment on inclusive, differential and simplified template cross section measurements of the Higgs boson are discussed. We cover the latest measurements for the bosonic decay channels in this presentation. Measurements of the Higgs boson couplings in the bosonic Higgs boson decay channels are also presented.
Recent studies of high-energy inclusive Higgs boson hadroproduction rates, incorporating fixed-order N$^3$LO QCD corrections, have demonstrated that high-energy resummation effects can contribute up to 10\% at the nominal energies of the FCC. This finding underscores the importance of resummation physics for electroweak processes at 100 TeV. We present new predictions for rapidity and...
An important aspect of the Higgs boson physics programme at the LHC is to determine all the properties of this particle, including its mass, which is a free parameter in the SM, and its width. This presentation will discuss the latest developments in measurements of the Higgs boson mass and width, with data collected by the CMS experiment at a centre of mass energy of 13 TeV. Both direct and...
We present two precision tools for the simulation of Higgs-pair
production via vector-boson fusion in the kappa framework for the
parameterization of non-standard Higgs couplings.
A new implementation of the process is developed in the framework of
the POWHEG-BOX program that can be used to provide predictions at the
next-to-leading order (NLO) of QCD matched to parton showers (PS).
In...
Extra light scalars are still not excluded by the existing experimental constraints, provided their coupling to the SM gauge bosons is sufficiently suppressed. They could be produced at the e$^+$e$^-$ Higgs factory in a scalar-strahlug process, analogous to the Higgs-strahlung process being the dominant production channel for the 125 GeV Higgs boson. This was selected as one of the focus...
We study the quantum properties of the Higgs-boson decays into four fermions via two vector bosons $(H\to VV^*\to 4f)$. In particular, we focus on the case of two different-flavour lepton pairs $(H\to ZZ^*\to \mu^+\mu^- e^+ e^-)$. We compute the quantum-information observables for the corresponding two-qutrit system $(ZZ)$ at next-to-leading order electroweak (NLO EW) accuracy in the SM. We...
We investigate the renormalization group scale and scheme dependence of the $H \rightarrow gg$ decay rate at the order N$^4$LO in renormalization-group summed perturbative theory, which employs the summation of all renormalization-group accessible logarithms including the leading and subsequent four sub-leading logarithmic contributions to the full perturbative series expansion. The...
The full set of data collected by CMS experiment at a centre of mass energy of 13 TeV allows searches for rare production modes of the Higgs boson, subdominant with respect the ones already observed at the LHC, by using a variety of decay modes profiting of the ones with largest expected branching fractions. We also discuss rare Higgs boson decay channel searches with the CMS experiment....
The virtual corrections for $gg \to HH$ at NLO QCD have been efficiently approximated using a Taylor expansion in the limit of a forward kinematics. The same method has been recently applied to the calculation of a subset of the NNLO corrections, which are desirable given the significant impact, at NLO, of the uncertainty due to the choice of the top mass renormalization scheme. In this talk,...
Measurement of the Higgs boson self interaction is one of the main goals at the high luminosity phase of LHC. A promising channel for this is the simultaneous production of two Higgs bosons from gluon-gluon fusion. For the interpretation of the measured data, a theoretical prediction of similar precision is needed. Following current projections this requires electroweak corrections at...
