Description
Conveners:
- Angela Burger (L2I Toulouse, CNRS/IN2P3, Universitรฉ de Toulouse)
- Mathieu Pellen (University of Freiburg)
- Elisabeth Petit (CPPM, Aix-Marseille Universitรฉ, CNRS/IN2P3)
Contact: eps-hep2025-conveners-T08-l@in2p3.fr
The study of Higgs boson production in association with one or two top quarks offers a unique opportunity to probe the interactions between the two heaviest particles in the Standard Model. This talk presents measurements of key Higgs boson properties - specifically the production cross section and CP nature - in events produced via tH and ttH processes. The results are based on the full Run 2...
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.
With the growing precision of experimental measurements, combining fixed-order perturbative calculations with parton-shower effects becomes essential for an accurate description of LHC phenomenology. In this talk, we present novel calculations of Higgs production in association with bottom quarks ($b\bar{b}H$), computed at NNLO accuracy and matched to parton showers (NNLO+PS), using the...
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...
Probing the Yukawa couplings between the Higgs boson and fermions is essential to understanding the origin of fermion masses. Higgs boson decays into pairs of quarks offer a direct window into these couplings and broader Higgs boson properties. This talk presents ATLAS measurements of Higgs decays into bottom quark pairs and searches for decays into charm quark pairs, based on the full Run 2...
LHCb is a spectrometer that covers the forward region of proton-proton collisions, in the pseudo rapidity range from 2 to 5. Thanks to its excellent vertex reconstruction system, it has already demonstrated its capability to identify heavy flavour jets. Moreover, the b- and c-jet identification is a crucial ingredient for the search of H->bb and H->cc at LHCb. In this talk, new methods used at...
The Standard Model predicts several rare Higgs boson processes, including decays into a Z boson and a photon, a low-mass lepton pair and a photon, or a meson and a photon. Observing these rare decays would offer new and complementary insights into the Higgs boson's coupling structure beyond the more commonly studied channels. In addition, searches for lepton-flavor-violating decays of 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 FCC-ee collider will deliver unparalleled sensitivity in Higgs boson decays, including couplings to quarks, gluons, and searches for invisible and rare decay modes. By employing advanced jet flavour tagging algorithms and exploiting a clean experimental environment, FCC-ee will measure the Higgs branching fractions to b, c, and gluon jets with sub-percent to few-percent accuracy. It will...
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...
We discussion an extension of the NNPDF4.0 parton distribution functions (PDFs) to approximate N$^3$LO. We assess the perturbative stability of the resulting PDFs and study the impact of missing higher order uncertainties, NLO QED corrections and the photon PDF, and we compare our results to the aN$^3$LO PDFs from the MSHT group. We present predictions for the total inclusive cross-section for...
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...
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...
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...
Higgs boson pair production (HH) plays a central role in probing the Higgs boson self-interactions, which are key to understanding the shape of the Higgs potential and the mechanism of electroweak symmetry breaking. This talk presents the latest results from the ATLAS experiment on non-resonant Higgs boson pair production, based on the full Run 2 dataset collected at\sqrt{s} = 13โฏTeV, with the...
The High-Luminosity LHC (HL-LHC) is expected to deliver an integrated dataset of approximately 3 abโปยน, enabling detailed studies of Higgs boson processes with unprecedented precision. Projections based on current analyses have been performed to estimate the expected measurement accuracy and identify potential limitations. The large data sample will also significantly enhance sensitivity to...
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,...
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...
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...
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...
e+e- colliders operating at energies below the di-Higgs production threshold can provide information on the trilinear Higgs self-coupling lambda via its loop contributions to single Higgs production processes and electroweak precision observables. We investigate how well a non-SM value of lambda can be determined indirectly via its loop contributions to a global EFT fit. Using a doublet...
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,...
High-energy $\gamma\gamma$- and $e\gamma$-collisions offer a rich phenomenological programme, complementary to $e^+e^-$ collisions at a linear collider both in kinematic as well as physics reaches. In particular, $\gamma\gamma$ collisions offer a unique setting to investigate properties of the Higgs boson(s). High polarisation of the photon beams (produced via Compton back-scattering) can be...
Many new physics models predict the existence of resonant states decaying into two bosons, including the Higgs boson or new scalar S bosons. These processes provide crucial signatures in the search for physics beyond the Standard Model and may offer insights into the mechanism of electroweak symmetry breaking. In this talk, the latest results from searches for resonant Higgs boson pair (HH)...
We investigate the size of interference effects between resonant and non-resonant contributions to di-Higgs production in the singlet extension of the Standard Model, where the additional heavy scalar provides a resonant channel. We find these interference contributions to have a non-negligible effect on the cross-sections and differential distributions. In order to allow for a computationally...
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...
The rare decay process $H \to Z \gamma$ has been investigated by both the ATLAS and CMS collaborations, with both reporting an event excess characterized by $\mu = 2.2 \pm 0.7$. This anomaly was initially attributed to potential modifications of the $HZ\gamma$ vertex. However, since the $H \to Z \gamma$ signal is reconstructed via the $H \to \ell \ell \gamma$ channel, background...
A general two Higgs doublet model (G2HDM) is adopted to study
$pp \to b H^\pm \to b b c +X$ at the Large Hadron Collider (LHC),
where $H^\pm$ is a charged Higgs boson,
$b$ represents a bottom quark or an anti-bottom quark,
and $c$ is a charm quark or an anti-charm quark.
In two Higgs doublet models with Type-II Yukawa interactions,
$g_{H^+ bc}$ is suppressed by $V_{cb} \simeq...
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...
This talk presents recent precision measurements of key properties of the Higgs boson using the full dataset of proton-proton collisions at โs = 13 TeV collected during Run 2 of the LHC by the ATLAS experiment. The Higgs boson mass is determined with high accuracy through its decays into two photons and four leptons, and the adopted analysis strategies and experimental techniques will be...
The FCC-ee programme is uniquely positioned to provide unprecedented precision on the fundamental properties of the Higgs boson. At the center-of-mass energies 240 and 365 GeV, the FCC-ee will produce millions of Higgs bosons via Higgs-strahlung and vector boson fusion. The clean experimental environment allows a model-independent measurement of the absolute ZH cross-section to better than...
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...
The Standard Model predicts the Higgs boson to be a CP-even scalar, but CP-odd contributions to its interactions with vector bosons and quarks are not yet strongly constrained. Various Higgs boson production and decay processes provide valuable tools to investigate the CP nature of these interactions. This talk presents the most recent measurements of the CP properties of Higgs boson...
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...
The Large Hadron electron Collider (LHeC) is the proposal to deliver electron-proton/nucleus collisions at CERN using the LHC hadron or nuclear beams and a 50 GeV electron beam from an Energy Recovery Linac (ERL) in racetrack configuration. While the 2021 update of its CDR [1] contemplated concurrent operation of electron-hadron and hadron-hadron collisions at the HL-LHC followed by standalone...
The FCC-hh, operating at a centre-of-mass energy of 84 TeV, will produce unprecedentedly large samples of single and double Higgs bosons, enabling detailed studies of rare decays and precise measurements of the Higgs self-coupling. With billions of single-Higgs events, FCC-hh will measure rare decays such as Hโฮผฮผ, Hโฮณฮณ, and HโZฮณ with percent-level precision. It will also significantly enhance...
This contribution discusses the physics potential of a future muon collider operating at a center-of-mass energy $\sqrt{s}= 10$ TeV for precision studies in the Higgs sector. Using a detailed detector simulation that incorporates the dominant sources of machine-induced background, the expected sensitivity to key Higgs processes is evaluated. These include the measurement of production cross...
