Conveners
Parallel: Additional Higgs bosons I
- Reisaburo Tanaka (Centre National de la Recherche Scientifique (FR))
Parallel: Yukawa couplings
- Yuji Enari (University of Tokyo (JP))
Parallel: Precision Higgs
- Lorenzo Tancredi (CERN)
Parallel: Di-Higgs
- James Frost (University of Oxford (GB))
Parallel: Effective field theory
- Michael Duehrssen-Debling (CERN)
Parallel: Beyond the Standard Model
- Frederic Alexandre Dreyer (Oxford)
Parallel: Additional Higgs bosons II
- Chris Hays (University of Oxford (GB))
With the large pp collision dataset collected at 13 TeV, detailed measurements of Higgs boson production can be performed in decays to bosons. This talk presents measurements of differential cross sections in Higgs boson decays to two photons or to four leptons, and a comparison to state-of-the-art theory predictions.
The prospect of using AI to utilise a greater fraction of the data available from colliders is very alluring,
particularly for events with limited statistics, such as Higgs decays.
On the topic of jet identification there are no shortage of attempts at such,
however, the `no free lunch' theorem is very central to use of AI.
Because of their boosted geometry, heavy highs decays can provide...
The reconstruction of the Higgs boson mass represents one of the key challenges in the H → ττ analysis, where instant τ-lepton decays contain non-detectable neutrinos. Precise mass reconstruction is a prerequisite for reasonable separation between the signal (alike gg→ H→ττ) and background (e.g. Z→ττ) processes. The ATLAS collaboration has developed an advanced technique for the Higgs boson...
An algorithm to obtain point and dispersion estimates for the energy of jets arising from bottom quarks is presented. b-jet energy regression is trained on a sample of b jets from simulated pp collisions. A multivariate regression estimator employing jet-composition information and the properties of the associated reconstructed secondary vertexes is implemented using a deep feed-forward neural...
We present Higgs to WW results from the analysis of the Run 2 data. We show differential measurements as well as simplified template cross section results and coupling constraints.
Analyses of collider data, often assisted by modern Machine Learning methods, condense a number of observables into a few powerful discriminants for the separation of the targeted signal process from the contributing backgrounds. These discriminants are highly correlated with important physical observables; using them in the event selection thus leads to the distortion of physically relevant...
The CMS Electromagnetic Calorimeter (ECAL) is a high resolution crystal calorimeter operating at the CERN LHC. It is responsible for the identification and precise reconstruction of electrons and photons in CMS, which were crucial in the discovery and subsequent characterization of the Higgs boson. It also contributes to the reconstruction of tau leptons, jets, and calorimeter energy sums,...
After the Higgs discovery at LHC in 2012, most of ATLAS Higgs analyses are focusing the attention on precision measurements of Higgs kinematic properties and on the search of new decay modes sensitive to physics Beyond the Standard Model (BSM). One of the most interesting channels is the Higgs boson decay into two b-quarks due to the large branching ratio (58%).
The observation of this...
This presentation will summarize the status and latest results of the searches for additional low-mass (m<125 GeV) Higgs bosons at CMS.
The most common decay of the Higgs is to two b quarks, making it an invaluable tool to gain more insight into Higgs properties and any shortcomings of the Standard Model. At ATLAS, analyses looking for di-jet resonances are limited to masses above a TeV, due to the high transverse momentum (pT) requirements of ATLAS jet triggers. However, sub-TeV mass regions can be reached if the resonance is...
The first CMS results for direct search of the H boson decaying into charm quarks are presented. The search is based on proton-proton collisions recorded by the CMS experiment at the CERN LHC in 2016, corresponding to an integrated luminosity of 35.9 fb−1 at sqrt(s) = 13 TeV. The analysis strategy targets events in which the Higgs boson is produced in association with a W or a Z boson,...
The High-Luminosity Large Hadron Collider (HL-LHC) is expected to deliver an integrated luminosity of up to 3000 fb-1. The very high instantaneous luminosity will lead to about 200 proton-proton collisions per bunch crossing (“pileup”) superimposed to each event of interest, therefore providing extremely challenging experimental conditions. Prospects for measurements of the properties of the...
We will talk about a novel way to avoid FCNC's at tree level in any multi-scalar extension of the Standard Model. This approach called Singular Alignment consists in taking all Yukawa matrices to be singularly aligned in flavor space. We mean by this that the Yukawa matrices are given as linear combinations of the rank 1 matrices that appear in the singular value decomposition of the mass...
We investigate in detail the recently computed non-factorizable NNLO QCD corrections to vector boson fusion. In particular we do an in-depth comparison with the already known factorizable corrections. We also investigate the validity of the eikonal approximation even when no VBF cuts are applied and estimate the non-factorizable contributions to the inclusive VBF cross section.
Studying the decay of the standard model Higgs boson to a pair of charm quarks is of vital importance as it directly probes the Yukawa coupling to second generation quarks. However, the hunt for H->cc is extremely challenging at the LHC due to large backgrounds. Recently, a search for H->cc has been performed by the CMS experiment, using advanced machine learning techniques and exploiting both...
Measuring the top quark Yukawa coupling is an important test of the standard model (SM) of particle physics and the production of a Higgs boson in association with top quarks (ttH) is the only channel that allows a direct measurement of this SM parameter. This talk will focus on the measurement of ttH where the Higgs boson decays to bottom quarks. The data were collected by the CMS experiment...
In any calculation in perturbative Quantum Chromodynamics (QCD) a choice needs to be made for the unphysical renormalisation scale, $\mu_R$. The Brodsky-Lepage-Mackenzie/Principle of Maximum Conformality (BLM/PMC) scale-setting procedure is one proposed method for selecting this scale and has previously been applied to a number of processes, including Higgs production. In this work we identify...
A number of extensions of the SM predict additional Higgs bosons. If massive enough, they can decay to a pair of top quarks with a high branching fraction. The interference with the SM tt background results in a characteristic peak-dip structure in the mtt lineshape. This talk will present a search for heavy additional Higgs bosons in the H→tt decay channel, performed with 36/fb of data...
We advocate the use of the Matrix Element Method for the determination of the top-quark Yukawa coupling. We show the constraining power of this method at hand of the single top-quark production in association with a Higgs boson.
This process is highly sensitive to the value of the Yukawa coupling and, in contrast to many other processes, allows the direct measurement of the relative sign of...
A detailed study of Higgs interference effects at the one-loop level in the 1-Higgs-Singlet extension of the Standard Model (1HSM) is presented for the WW and ttbar decay modes with fully leptonic WW decay. We explore interference effects for benchmark points with a heavy Higgs mass that significantly exceeds 2mt. In the WW channel, the Higgs signal and the interfering continuum background are...
As the integrated luminosity recorded by the LHC experiments increases, systematic uncertainties play an ever more important role in Higgs boson measurements and searches. Several measurements are already limited by systematic uncertainties. Among these, theory uncertainties on the signal and background modeling play an important role. This talk discusses a few examples of analyses where...
We consider the next-to-leading order QCD corrections to Higgs boson pair production, using our recent calculation of the form factors in the high-energy limit. We compute the virtual corrections to the partonic cross section, applying Padé approximations to extend the range of validity of the high-energy expansion. This enables us to compare to the exact numerical calculation in a significant...
This talk will discuss an effective field theory interpretation of simplified template cross section (STXS) stage 1.1 measurements at CMS. The Higgs Effective Lagrangian (HEL) is used to parameterise our lack of knowledge of the electroweak symmetry breaking sector by extending the Standard Model Lagrangian to higher orders in momentum expansion.
The status of STXS stage 1.1 measurements at...
The total and partial inclusive Higgs widths are crucial observables for the study of properties of the Higgs boson. In particular, they play a key role in global Higgs analyses within the framework of the Standard Model Effective Field Theory (SMEFT).
This talks presents the first full calculation of the Higgs width for two and four-body decays through vector currents, at leading order in...
With Higgs boson couplings to vector bosons and heavy fermions being increasingly well-measured at the LHC, the SM Higgs potential is explored further than ever. Yet, the Higgs trilinear self-coupling is still largely unconstrained due to the small cross-section for Higgs boson pair production. I present NLO QCD corrections to Higgs pair production with the full top-quark mass dependence...
Violation of CP invariance is one of the Sakharov conditions needed to explain the observed baryon asymmetry in our universe. While CP violation is already realised in the Standard Model (SM) via the CKM matrix, its strength is not sufficient to explain the amount of observed baryon asymmetry. Hence, it is important to search for new sources of CP violation in the Higgs sector.
The...
After the discovery of the Higgs boson, one of the main targets of particle physics is the measurement of the Higgs boson couplings to fermions and vector bosons. Moreover, also of great interest is the observation of the interaction of the Higgs boson with itself, known as the Higgs boson self-coupling. The self-coupling is very loosely constrained by EWK precision measurements therefore new...
The most recent results from searches for non-resonant production of Higgs boson pairs at CMS will be presented.
The tau anomalous magnetic moment g–2 strikingly evades experimental measurement, but its larger mass implies greater sensitivity to new physics than the muon counterpart, which reports a longstanding 3–4 sigma tension. Interestingly, the only two dimension-6 SMEFT operators that modify tau g–2 at tree-level involve Higgs–gauge–fermion couplings. We propose a new strategy using the LHC as a...
The latest results on production of Higgs boson pairs at 13 TeV by the ATLAS experiment are reported, including a combination of six different decay modes. Results include bbtautau, bbbb, bbgamgam, bbWW, WWWW and WWgamgam final states, and they are interpreted both in terms of sensitivity to the SM and as limits on kappa_lambda, a scaling of the triple-Higgs interaction strength. Future...
After the discovery of the Higgs boson, new searches can now change their focus towards using it as a tool to probe both the Standard Model and new physics. One of such probes is the search for pair production of Higgs bosons. With the largest branching fraction, the bb̅bb̅ final state is one of the leading candidates to observe this process This talk will feature a search for Higgs boson pair...
Very generically the same BSM physics that modifies Higgs couplings can also modify other electroweak couplings. A concrete example is given about the contact interaction operators in the Standard Model Effective Field Theory. In this respect, the electroweak precision observables (EWPOs) such as A_l (left right asymmetry in electron Z coupling) and Gam_l (partial width of Z to leptons) turn...
This talk presents a search for an additional heavy Higgs boson decaying to a pair of SM Z bosons, covering heavy Higgs boson masses in the range between 200 GeV and 2 TeV. To maximize the sensitivity the search combines the two fully leptonic decay channels of the ZZ pair – ZZ→ 4l and ZZ → llvv, where l stands for a charged light lepton. The 4l channel profits from the very good resolution of...
Several theories beyond the Standard Model predict lepton-flavor violating decays of the Higgs boson. This talk will present the results of searches for these decays based on pp collision data collected at 13 TeV.
We review recent progress in the calculation of the MSSM Higgs boson masses for low MA and tanb using the THDM as low-energy EFT. As an application of this calculation, we present two new Higgs benchmark scenarios valid in the region of low tanb. While all SUSY masses are chosen relatively heavy in the first scenario, the second scenario features light neutralinos and charginos. Both scenarios...
The discovery of the Higgs boson with the mass of about 125GeV 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 addressing this fact introduce additional Higgs-like bosons which can be either neutral, singly-charged or even...
Type-II seesaw model, a well motivated new physics scenario to address the origin of neutrino mass issues, includes an extra $SU(2)_L$ complex triplet scalar along with the SM particles. We show that this model can easily accommodate an absolutely stable vacuum until the Planck scale, however with strong limit on the exotic scalar masses and the corresponding mixing angle. We examine the model...
Charged Higgs boson $(H^{\pm})$, which exists in many Supersymmetric (SUSY)/Non-SUSY models, is one of the most important evidences for new physics beyond the Standard Model. This talk is about a numerical study over the constrained Minimal Supersymmetric Standard Model (CMSSM), next-to-MSSM (NMSSM) and U(1) extended MSSM (UMSSM). In this work, we investigate the allowed mass ranges of the...
The discovery of the Higgs boson at the LHC has opened up the possibility for new physics to be discovered through its couplings and decays. In particular, it could serve as a portal to dark sectors by coupling to invisible particles or even dark matter. We consider 2 models where an interesting characteristic signature is that of di-Higgs production in association with missing energy....
We investigate the predictions on the mass spectrum and Higgs boson decays in the supersymmetric standard model extended by $U(1)_{B-L}$ symmetry (BLSSM). The model requires two singlet Higgs fields, which are responsible for the radiative breaking of $U(1)_{B-L}$ symmetry. It predicts degenerate right-handed neutrino masses ($1.7-2.2$ TeV) as well as the right-handed sneutrinos of mass < 4...
We study and compare various Z′ models arising from SO(10), focusing in particular on the Abelian subgroup U(1)R×U(1)B-L, broken at the TeV scale to Standard Model hypercharge U(1)Y. The gauge group U(1)R×U(1)B-L, which is equivalent to the U(1)Y×U(1)χ in a different basis, is well motivated from SO(10) breaking and allows neutrino mass via the linear seesaw mechanism. Assuming supersymmetry,...
In this talk we discuss the model with three Higgs doublets, focusing on the particular case in which only one doublet acquires an expected vacuum value (VEV), preserving a parity $Z_N$. The other two doublets do not develop a VEV and are, therefore, inert. The lightest field of the inert doublets is stable and a proper dark matter (DM) candidate. For the case of a $Z_2$ symmetry, we discuss...
I will discuss a novel mechanism for the production of the Higgs boson in inclusive hadronic collisions, which utilizes the presence of multi-connected intrinsic heavy quarks in the proton's
$|uud Q \bar Q>$ light-front wave function(LFWF). In these inclusive reactions, the Higgs boson acquires the momentum of both the heavy quark and antiquark and thus carries 80\% or more of the...
A study into the feasibility of measuring the Higgs self-coupling, lambda_hhh using the high luminosity LHC is presented.
Reconstructing the variation in the di-Higgs invariant mass distribution with
$\lambda_{hhh}$ is essential to measuring this parameter well. Simulated signal
data is used to demonstrate the challenges in doing this.
The above simulated signal data is then used in...
