Higgs data can provide better constrains on some top quark operators than top data. Since in Higgs observables various SMEFT operators enter, differential Higgs data might prove useful in global fits including those operators. In addition, such analysis could shed light on the chiral structure of the (eventual) heavy new physics beyond the Standard Model.
We calculate the dominant...
The mass of the Higgs boson can be measured in the Higgs to four leptons and Higgs to two photons decay channels, where the excellent mass resolution can be used to reconstruct the Higgs boson invariant mass. The same decays can be used to measure the Higgs boson natural width, either by exploiting the offshell Higgs contribution to the four leptons and two leptons plus two neutrinos...
We present an updated global SMEFT analysis in the Higgs and Electroweak sectors with the SFitter framework.
The main result we present is the comparison of the results obtained with a frequentist and with a bayesian approach. The implementation of Bayesian inference in the SFitter framework is one of the main novelties of this work, and it is motivated by its greater scalability to...
The latest measurement of the Higgs mass in the 4l final state at CMS will be presented. The prospects with the HL-LHC on the Higgs mass sensitivity will also be shown.
With the full Run 2 pp collision dataset collected at 13 TeV, very detailed measurements of Higgs boson coupling and kinematical properties can be performed, exploiting a variety of final states and production modes, probing different regions of the phase space with increasing precision. Coupling, fiducial and differential measurements can then be combined to exploit the specific strength of...
We present the most recent searches for CP and anomalous couplings (AC) in Higgs boson production and decay. Couplings of the Higgs boson to both vector bosons and fermions will be discussed in various production channels and final states. The results have been performed with data from the full CMS Run 2 dataset, corresponding to an integrated luminosity of 138 fb−1 at a center-of-mass energy...
In the absence of direct observations of new physics beyond the Standard Model, interpretations of results using Effective Field Theories can be a powerful tool to place near-model-independent constraints on new physics scenarios, or better observe deviations from the Standard Model and have it interpreted in terms of specific new interactions. This talk presents Effective Field Theory...
The most recent fiducial differential cross section measurements performed in the $\mathrm{H}\rightarrow{\rm Z}{\rm Z}\rightarrow4\ell$ ($\ell={\rm e},\mu$) decay channel are presented. The results have been obtained using data collected by the CMS experiment, corresponding to an integrated luminosity of 138 fb-1 at a centre of mass energy of 13 TeV. The fiducial cross section is measured with...
The VBF production mode has the 2nd largest production cross section for Higgs bosons in the SM at the LHC, and provides a way to study the Higgs boson's interactions with vector bosons. In this talk, recent measurements of the VBF Higgs boson production mode at CMS will be discussed. All measurements make use of data collected during Run 2 of the LHC.
The electroweak symmetry-breaking sector is one of the most promising and uncharted parts of the Standard Model; but it seems likely that new electroweak physics may be out of reach of the present accelerator effort
and the hope is to observe small deviations from the SM. Given that, Effective Field Theory becomes the logic method to use, and SMEFT has become the standard. However, the most...
We analyse the sensitivity to beyond-the-Standard-Model effects of hadron-collider processes involving the interaction of two electroweak (V) and two Higgs (H) bosons, VVHH, with V being either a W or a Z boson.
We examine current experimental results by the CMS collaboration in the context of a dimension-8 extension of the Standard Model in an effective-field-theory formalism. We show that...
This talk will present a measurement of the charge conjugation and parity ($CP$) properties in the Higgs boson interaction with $\tau$ leptons. The Yukawa interaction is generalized with a single mixing angle parameter $\phi_{\tau}$ to describe $CP$-odd interactions between the Higgs boson and $\tau$ leptons. The study is based on a measurement of $CP$-sensitive angular observables defined by...
Diboson production processes provide good targets for precision measurements at present and future hadronic colliders. We consider $Vh$ production, focusing on the $h \to b\bar b$ decay channel, whose sizeable cross section makes it easily accessible at the LHC. We perform an improved analysis combining the 0-, 1- and 2-lepton channels with a scale-invariant $b$-tagging algorithm that allows...
Recent years have seen an unprecedented development of techniques devoted to identifying jets from the hadronization of heavy flavor quarks. This was made possible by the extensive usage of modern machine learning techniques. In particular, the identification of heavy resonance final states involving a pair of bottom or charm quarks largely benefited from these developments. In addition,...
The High-Luminosity LHC (HL-LHC) era will herald significant increases in both the instantaneous luminosity and the number of interactions per bunch crossing. To cope with these significantly more complex conditions, detector upgrades are planned to maintain and surpass the current physics performance. The replacement of the current Inner Detector with a new all-silicon Inner Tracker (ITk) is...
This talk will present the latest CMS results on the measurement of Higgs boson production with H->bb decays. It will consider the Higgs boson production via gluon fusion in the boosted topology (ggF Hbb), via vector boson fusion (VBF Hbb), in association with a vector boson (VH Hbb), and with a top quark pair (ttHbb). In addition, the talk will discuss the latest results of the search for the...
The FCC-ee offers powerful opportunities to determine the Higgs boson parameters, exploiting over 106 e+e−→ZH events and almost 105 WW→H events at centre-of-mass energies around 240 and 365 GeV. This essay spotlights the important measurements of the ZH production cross section and of the Higgs boson mass. The measurement of the total ZH cross section is an essential input to the absolute...
The measurement of the H->bbbar decay rate by ATLAS and CMS offers an opportunity to test the scale evolution or "running" of the bottom quark mass. With an excellent mass sensitivity, reduced dependence on alpha_s and a clearly identifiable scale, the Higgs decay process is the ideal laboratory to extract a high-scale quark mass. The mass at the scale given by the Higgs boson mass, mb(mH) is...
Many physics analyses using the CMS detector at the LHC require accurate, high resolution electron and photon energy measurements. Excellent energy resolution is crucial for studies of Higgs boson decays with electromagnetic particles in the final state, as well as searches for very high mass resonances decaying to energetic photons or electrons. The CMS electromagnetic calorimeter (ECAL) is a...
With technically mature design and well understood physics program, ILC is realistic option for realization of a Higgs factory. With a unique physics reach of a linear collider, ILC meaningfully complement projections for HL-LHC. Energy staged data collection, employment of beam polarization and capability to reach a TeV center-of-mass energy enable unique precision to probe BSM models above...
In the years 1922-1926 Enrico Fermi, then in his early twenties, was scientifically active in Pisa, Gottingen, Leiden and Florence. Apart from his experimental thesis on X rays, most of his research activity was purely theoretical, and covered a wide spectrum of issues, from general relativity (Fermi coordinates, electromagnetic mass) to statistical mechanics (Fermi statistics), from atomic...
LHCb is a spectrometer that covers the forward region of proton-proton collisions, in the pseudo rapidity range from 2 to 5. Thanks to the relatively background-free events in the high mass region, the precise reconstruction, and the trigger system with low energy thresholds, LHCb is the ideal place to search for (exotic) Higgs decays in a complementary space with respect to ATLAS and CMS. In...
With the discovery of the Higgs boson at the CERN Large Hadron Collider (LHC), the particle spectrum of the Standard Model (SM) is complete. The next target at the energy frontier will be to study the Higgs properties and to search for the next scale beyond the SM. Experimentally, the $H\to c \bar{c}$ channel would be extremely difficult to dig out because of both the weak Yukawa coupling and...
A muon collider provides an interesting opportunity to test various aspects of Higgs physics and potential BSM models. For a muon collider, Vector-boson fusion provides the dominant channel for the production of Higgs bosons. We calculate the lowest and higher order Higgs jet distribution as a function of jet invariant mass for the super-renormalizable splitting $h\rightarrow hh$ and compare...
The muon collider is the ideal machine for reaching multi-TeV centre-of-mass energy and high luminosity lepton collisions, thanks to the low beamstrahlung and synchrotron radiation loss compared to $e^+$ $e^-$ colliders.
In such conditions, the number of produced Higgs bosons will allow to measure its couplings to fermions and bosons with an unprecedented precision.
However, in order to...
The most recent direct searches for the H→cc process by the CMS Collaboration will be presented. The results are obtained using the full Run 2 LHC data collected in proton-proton collisions at a center of mass energy of 13 TeV, targeting the associated production of the Higgs boson with a Vector boson (W or Z boson) and, for the first time, the gluon fusion production mechanism. To fully...
The determination of the Higgs self-coupling from di-Higgs events with very high precision is one of the clearest benchmarks for the FCC-hh. Its potential has been well established already in several final states. In this talk studies into final states of the di-Higgs system which involve neutrinos are presented. The benefit of studying yet another di-Higgs final state is two-fold: First, any...
Testing the Yukawa couplings of the Higgs boson to fermions is essential to understand the origin of their masses, and studies are made by exploring the properties of the Higgs boson decays to quark pairs. The talk presents various measurements of the Higgs boson decays to two bottom quarks and searches for Higgs boson decays to two charm quarks by the ATLAS experiment using the full Run 2...
The large dataset of about 3 ab-1 that will be collected at the High Luminosity LHC (HL-LHC) will be used to measure Higgs boson processes in detail. Studies based on current analyses have been carried out to understand the expected precision and limitations of these measurements. The large dataset will also allow for better sensitivity to di-Higgs processes and the Higgs boson self coupling....
I present the computation of the two-loop helicity amplitudes for Higgs boson production in association with a bottom quark pair. This work is of relevance to the precision studies of the bottom-quark Yukawa coupling, such as the analysis of new physics models which modify the strength of this coupling. I give an overview of the method and describe how we overcome the computational bottlenecks...
We present results for Higgs boson pair production in gluon fusion
at NLO (2-loop) QCD including operators in the Standard Model Effective Field Theory (SMEFT) framework.
Contributions from subsets of higher order terms in $\frac{1}{\Lambda^2}$,
such as squared dimension-6 operators at cross section level and double operator insertions at amplitude level, are used as a proxy
for the...
One of the main backgrounds in the multi-lepton decay channels of ttH production is ttW production. There is a slight tension between the theoretical predictions for this processes and what is needed to describe the data. In this talk the main cause for this tension will be outlined, and a solution, based on an improved version of the FxFx merging technique, will be proposed. This talk is...
The latest results on non-resonant Higgs boson pairs (HH) production in the bbtautau final state (where one Higgs boson decays into a pair of bottom quarks and the other decays into a pair of tau leptons) as well as in the multilepton final state will be presented. Both the gluon fusion and vector boson fusion production mechanisms are investigated. The bbtautau final state gives a good...
Several physics scenarios beyond the Standard Model predict the existence of new particles that can subsequently decay into a pair of Higgs bosons. This talk summarises ATLAS searches for resonant HH production with LHC Run 2 data. Several final states are considered, arising from various combinations of Higgs boson decays.
Precision studies of the properties of the Higgs bosons may provide a unique window for the discovery of new physics at the LHC. New phenomena can in particular be revealed in the search for lepton-flavor-violating or exotic decays of the Higgs bosons, as well as in their possible couplings to hidden-sector states that do not interact under Standard Model gauge transformations. This talk...
This talk will present the latest CMS results on the search of non-resonant and resonant di-Higgs production, with one of the Higgs boson decaying to a pair of photons. The search for resonant di-Higgs production covers both the final state with two 125 GeV Higgs bosons as well as the final state with a 125 GeV Higgs boson and a different new scalar. The diphoton decay channel has excellent...
Although the Higgs boson decay to four neutrinos predicted by the SM is inaccessibly small at the LHC, the Higgs boson branching fraction to invisible detector signatures can be significantly enhanced under various BSM scenarios. Searches for Higgs to invisible probe in particular Higgs portal models where the Higgs boson couples directly to dark matter, and the resulting constraints from the...
At the LHC, a large range of different Higgs boson production modes and decay channels are studied. To obtain a full overview of the couplings between the Higgs boson and other particles, the data from these individual measurements of production and decay channels are combined. This is also the case for searches for HH production, where even more different final state combinations are...
In the Standard Model, the branching ratio for Higgs boson decays to invisible final states is very small, but it can be significantly enhanced in extensions of the Standard Model. This talk presents searches for Higgs boson decays to invisible final states by the ATLAS experiment using the full Run 2 dataset of pp collisions collected at 13 TeV at the LHC, as well as their combination and...
In the Standard Model, the ground state of the Higgs field is not found at zero but instead corresponds to one of the degenerate solutions minimising the Higgs potential. In turn, this spontaneous electroweak symmetry breaking provides a mechanism for the mass generation of nearly all fundamental particles. The Standard Model makes a definite prediction for the Higgs boson self-coupling and...
This talk presents the results of a direct search for lepton-flavour-violating decays of the Higgs boson to e tau and mu tau final states with the ATLAS detector at the LHC. Both leptonically and hadronically decaying tau leptons are included and two different background estimation techniques are employed: A direct estimation of the background using MC, and a data-driven approach exploiting...
The Higgs sector is a possible avenue for searches of BSM sources of CP violation, with V(V=W,Z)H production offering a way to separately probe the HWW and HZZ interactions, not possible in channels such as weak boson fusion. In this work, we search for CP-violating (CP-odd) EFT components in the HWW interaction via leptonic WH production - W(-> l \nu)H. This is a channel which allows high...
Several Beyond Standard Model theories motivate an extended Higgs sector. Searches for additional Higgs bosons, based on these predictions, constitute an intensive subject of study within CMS. The two Higgs doublet models (2HDM) are by now heavily constrained. But models, where the two Higgs doublets are extended by one additional Higgs singlet complex field (2HDM+S), remain consistent with SM...
The CP properties of the Higgs boson couplings to weak bosons can be probed in production by exploiting the Vector Boson Fusion process, or by studying the properties of the Higgs decay to two Z bosons. This talk presents the measurement of the CP properties to weak bosons by the ATLAS experiment using Higgs to two photon decays in VBF production, or Higgs to four leptons decays, and the full...
Extensions of the Standard Model Higgs sector with a second Higgs doublet allow for the existence of charged Higgs bosons as well as heavy pseudoscalar Higgs bosons. The heavy pseudoscalars can decay into a Z boson and a lighter scalar Higgs boson, which could be either the established 125 GeV state, or a new heavier sibling. Charged Higgs bosons are probed in various final states, including...
Measurements of the inclusive and differential fiducial cross sections of Higgs boson decaying to a pair of photons are presented. The analysis is performed using proton-proton collisions data recorded with the CMS detector at the LHC at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 138 fb−1. The measurements performed in fiducial regions target different...
The discovery of the Higgs boson with the mass of about 125 GeV completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many measurements, it is not capable to solely explain some observations. Many extensions of the Standard Model addressing such shortcomings introduce additional neutral Higgs-like bosons. The current...
Although many suggestions for BSM searches at future colliders exist, most of them concentrate on additional scalars that have masses higher than the current SM scalar mass. I will give a short overview on the current status of models and searches for scalars with masses below this. Based on https://arxiv.org/abs/2205.09687
Higgs boson decays to two photons can be selected with high efficiency, and the very good invariant mass resolution allows a robust subtraction of the continuous backgrounds, making this channel an excellent tool both for precision measurements and searches for new phenomena involving the Higgs boson. This talk presents measurements of Simplified Template Cross Sections, differential and...
The Higgs boson decays to two W bosons has the largest bosonic branching fraction and can be used to perform some of the most precise measurements of the Higgs boson production cross sections. This talk will present Higgs boson cross section measurements by the ATLAS experiment in the H->WW* decay channel using pp collision data collected at 13 TeV, including those for different Higgs boson...
We discuss theoretical and experimental constraints on extended Higgs models with large quantum corrections. Such large quantum effects play an important role to realize the strongly first-order electroweak phase transition. We use a new Higgs EFT describing the strongly first-order phase transition in order to discuss model independent results. We show that the parameter region satisfying the...
Recent analyses on high-energy inclusive Higgs-boson rates in proton collisions via the gluon fusion channel, matched with the state of-the-art fixed-order N$^3$LO accuracy, have shown that the impact of high-energy resummation corrections reaches 10% at the FCC nominal energies. This supports the statement that electroweak physics at 100 TeV is expected to receive relevant contributions from...
With the large data set collected during Run 2 of the LHC, it is possible to go beyond inclusive Higgs boson cross section measurements. One way in which this is done is through the simplified template cross sections (STXS), which make use of several variables to divide up the phase space of the different Higgs boson production modes. The binning is designed to be particularly sensitive to...
The Standard Model predicts several rare Higgs boson decay channels, among which are decays to a Z boson and a photon, H to Zgamma, and to a low-mass lepton pair and a photon H to llgamma, and a pair of muon. The observation of Zgamma decays could open the possibility of studying the CP and coupling properties of the Higgs boson in a complementary way to other analyses. In addition, the search...
At high energies, fixed-order predictions for the production of a Higgs boson together with one or more jets suffer from large logarithms in invariant masses over transverse momenta. We resum these high-energy logarithms to all orders using the High Energy Jets (HEJ) framework, retaining the exact dependence on the top-quark mass. We compare our predictions to ATLAS and CMS measurements at 8...
Collider experiments will achieve percent level precision measurements of several processes key to answer some of the most pressing questions of contemporary particle physics. In this talk I will show that the capability to predict and describe such observables at next-to-next-to-next-to-leading order (N3LO) in QCD perturbation theory is crucial to fully exploit these experimental...
Extensions of the Higgs sector beyond the standard model, in particular models with two Higgs doublets and possibly additional singlets, predict the existence of additional particles in the Higgs sector. These additional particles include a neutral Higgs boson with a large allowed mass region. When the mass of the neutral Higgs boson is less than half the Higgs boson mass, an important search...
The MicroBooNE detector is a 60 m$^3$ active volume liquid argon time projection chamber located at Fermilab approximately 100 m from a high intensity stopped kaon source. We use this setup to search for a light, long-lived scalar boson that mixes with the Higgs boson and could be produced in rare kaon decays. We present results of our search for different dilepton signatures of these scalar...
We present NLO QCD corrections to ZH production in gluon fusion, including the effects of the top-quark mass. Our results are obtained by combining virtual corrections evaluated numerically using sector decomposition with virtual corrections obtained in an high-energy expansion.
We discuss the uncertainties related to the top-quark mass renormalization scheme and we present phenomenological results.
We present the calculation of the virtual QCD corrections to gg → HH and gg → ZH. The results are obtained combining an expansion in the small transverse momentum of the final particles with an expansion valid at high energies, and extending the range of validity of both expansions using Padé approximants. This approach can reproduce the available numerical results retaining the exact top...
We study exotic Higgs decays $h \to Z X$, with $X$ an invisible beyond the Standard Model (SM) particle, resulting in a semi-dark final state. Such exotic Higgs decays may occur in theories of axion-like-particles (ALPs), dark photons or pseudoscalar mediators between the SM and dark matter. The SM process $h\to Z\nu\bar{\nu}$ represents an irreducible ``neutrino floor'' background to these...
Higgs-boson pair production at hadron colliders is dominantly mediated by
the loop-induced gluon-fusion process gg→HH that is generated by heavy
top loops within the Standard Model with a minor per-cent level
contamination of bottom-loop contributions. The QCD corrections turn out
to be large for this process. In this talk, we discuss the
top-Yukawa-induced part of the electroweak...
In this talk, I will present a first look at the two-loop electroweak
corrections to Higgs boson pair production in gluon-fusion, which
might have a sizeable impact on the cross section. We have performed an
analytic calculation of the two-loop diagrams contributing
to gg->HH where a virtual Higgs boson is exchanged in the top quark loop.
I will briefly describe our method used to solve...
The search for dark photon (y_d) in resonant mono-photon signatures from the Higgs boson decay H->yy_d in the ZH production mode with Z->ll has been performed using 139 fb-1 of proton???proton collision data recorded with the ATLAS detector at a centre-of-mass energy sqrt(s) = 13 TeV at the Large Hadron Collider during the 2015-2018 Run 2. A global fit to the Boosted Decision Tree (BDT) score,...
The determination of the Higgs self-couplings are of primary importance in particle physics and cosmology. They characterise the Higgs potential and thus the electroweak symmetry breaking mechanism. Moreover, the structure of the potential could shed some light on the naturalness problem and the self-couplings control the properties of the electroweak phase transition, determining its possible...
